← LEDGERLANDSTHE POSITION BUILD STUDIES / 2026

Evidence → commitment

The Darwin
playbook.

What became knowable when Abhishek Trehan increased exposure—and what still had to go right.

23 quartersQ4 2020 – Q2 2026
15 casesTEN DEEP DIVES + FIVE OTHER POSITIONS
413 documentsCLINICAL & OWNERSHIP SOURCE ARCHIVE

Holdings observed. Motives inferred. This is a reconstruction from public evidence, not a manager’s disclosed investment memo. Estimated appreciation is not audited P&L.

The evidence spans early human signals, pivotal results and actual launch demand. There is no single “buy after Phase 3” rule.

Read the Baker Brothers playbook →Holdings workbook ↓

November 7, 2026. Follow-up to the complete Darwin 13F history. The strongest recurring pattern is increasing exposure when human evidence makes a large future drug business more credible, while important clinical, regulatory or commercial work still lies ahead. The evidence does not support a single rule of buying only after Phase 3 success: Verona is a launch-adoption case, while Vaxcyte, Acceleron and Ambrx were earlier in the proof process.

This reconstructs the public opportunity set, not Trehan’s private reasoning. I found no contemporaneous Darwin letter or interview explaining these individual decisions. Clinical disclosures and financing terms are facts; the investment interpretation is explicitly my inference. First appearances within a result quarter do not establish the trade happened after the result. Several 13D/G filings tighten the timing.

Research base: 413 archived SEC filing documents and exhibits across 15 companies, selected Darwin ownership filings, Revolution earnings transcripts, and dated issuer disclosures. Sources are linked beside each case.

Ownership figures come from the validated 23-quarter holdings study and source ledger (holdings workbook). Weights refer to the 13F book, not fund NAV. This is a deliberately selected review of the leading winners and large commitments, not a statistical backtest of all 67 security histories.

The common investment logic

  1. A stronger answer to a consequential question. Insmed supplied pivotal evidence of fewer exacerbations; Revolution supplied randomized survival evidence; Verona supplied actual prescription and refill behavior. These changed the kind of uncertainty an investor was underwriting.

  2. A plausible large commercial role. These drugs could become part of routine treatment, address a previously untreated condition, expand the population served, or create a differentiated platform with follow-on uses. “Large unmet need” alone was insufficient; a measured human or commercial signal supported the story.

  3. More opportunity remained after the first proof. Brensocatib still had approval and launch ahead; daraxonrasib had earlier-line and other-tumor opportunities; Cidara had a pivotal program; Vaxcyte had broader serotype coverage; Verona had years of possible penetration. Expansion was optionality, not proof of success in those additional settings.

  4. The company could finance the next step. Ambrx is direct evidence: Darwin supplied capital. Vaxcyte, Cidara, Insmed and Belite also raised capital around relevant proof points. Their offerings could remove financing uncertainty and provide liquidity, but only Ambrx participation is specifically established here.

  5. A willingness to increase exposure after prices rose. Ambrx’s new commitment at $13.93 followed a previously disclosed average cost near $4.17. Insmed’s main Q3 2024 build followed the May result. This suggests reassessing risk-adjusted value rather than anchoring solely to an earlier price. It does not prove the stocks were cheap or reveal Darwin’s valuation model.

  6. Concentration is followed by reassessment, not automatic permanent ownership. Insmed’s reported shares were subsequently cut sharply and RVMD became the dominant holding. That establishes an exposure change, not the motive for each sale or direct funding of one purchase by another.

What was knowable during each commitment

Company Main accumulation Type of new evidence What remained to prove
Insmed (INSM) Q3 2024, then through 2025 Pivotal efficacy → approval and commercial preparation Approval, pricing, adherence and actual penetration were still uncertain in 2024
Revolution Medicines (RVMD) Q2 2026 Randomized survival benefit → potential oncology franchise 13Fs do not identify whether every Q2 purchase followed April 13; some could have occurred in the first twelve days of the quarter
Ambrx (AMAM) March and June 2023 Early human signal + direct development financing Three patients are not robust efficacy proof
Cidara (CDTX) Q3 2025 Large randomized Phase 2 → simpler, financed pivotal path NAVIGATE involved unvaccinated healthy participants
Verona (VRNA) Q1 2025 Approved drug → demonstrated launch demand Early launch results still needed to translate into persistent treatment, payer access, sustainable net pricing and broader adoption
Vaxcyte (PCVX) Q1 2024 Validated earlier candidate → funded next-generation trial VAX-31 immunogenicity, added-serotype interference, reproducible commercial manufacturing and eventual pediatric efficacy/immunogenicity were not settled
Acceleron (XLRN) Q1–Q3 2021 Randomized Phase 2 → potential new backbone therapy The pivotal STELLAR result and later regulatory approval were years away during the first build
Belite Bio (BLTE) Initial large Q4 2025 position Pivotal anatomical endpoint → first potential therapy Regulatory acceptance of the endpoint, clinical meaningfulness over time, vision outcomes and the independent geographic-atrophy trial remained material risks
Abivax (ABVX) Initial large Q3 2025 position Two pivotal induction successes → maintenance and filing opportunity The induction result did not establish maintenance efficacy or superiority to every competing IBD drug
Roivant (ROIV) Initial Q1 2026 position; no subsequent ramp Several clinical assets + regulatory progress + financial optionality The allocation might have preceded some March announcements

Insmed (INSM)

Observed ownership: 3.541m shares in Q2 2024 → 10.497m in Q3 (+196%) → 12.961m in Q4; 19.345m by Q2 2025 and 20.933m by Q4. A Schedule 13G filed September 3, 2024, with an August 23 event date, reports 9.718m shares, tightening the timing of the major build.

Public evidence available then:

  • May 28, 2024: the randomized Phase 3 ASPEN study met its primary endpoint at both brensocatib doses. Annualized pulmonary exacerbations were reduced by 21.1% at 10 mg and 19.4% at 25 mg versus placebo. These were exacerbation reductions, not reductions in mortality.
  • June 4: the company held a dedicated commercial presentation. It argued for more than $5bn of peak brensocatib sales potential, described a large diagnosed bronchiectasis population and emphasized physician/patient overlap with its existing ARIKAYCE business. This is management’s commercial thesis, not an independently verified sales forecast.
  • July 3: additional ASPEN data supported less lung-function decline at the 25 mg dose. By the Q3 build, the pivotal result, fuller data and launch plan were all public. The $650m base offering priced May 30 also improved financing visibility.
  • February 6, 2025: FDA priority review with an August 12 target date. June 10: TPIP Phase 2b met its primary and secondary endpoints, including a 35% placebo-adjusted reduction in pulmonary vascular resistance and a 35.5-meter improvement in six-minute walk distance. The Q2 2025 addition overlapped this second-asset result; it does not prove the whole addition occurred afterward.

My interpretation: The central underwriting question had shifted from whether brensocatib worked to how large a new chronic pulmonary franchise could become. Existing pulmonary relationships reduced the commercial leap. Later TPIP evidence offered another substantial asset behind the first one. This best fits increasing exposure as clinical and execution uncertainty fell while potential business value remained large.

Still unresolved: Approval, pricing, adherence and actual penetration were still uncertain in 2024. TPIP remained a Phase 2 asset. Management’s peak-sales estimates are not Darwin’s own forecasts. The initial Q2 entry could have preceded the May result, but the much larger Q3 addition definitely followed it.

Confidence: High that the major build followed pivotal proof; inferred commercial rationale, not a disclosed investment memo.

Sources: May 28 ASPEN result; June 4 commercial presentation; July 3 fuller ASPEN data; May 30 financing; February 2025 priority review; June 2025 TPIP result; Darwin September 3 13G.

Revolution Medicines (RVMD)

Observed ownership: 2.211m shares in Q1 2026 → 10.630m in Q2 (+381%). The initial stake preceded the Phase 3 result; the major increase occurred in the result quarter.

Public evidence available then:

  • February 25, 2026: management still described the completed RASolute 302 enrollment and an expected first-half readout. Thus, the initial Q1 position carried the pivotal binary risk.
  • April 13: daraxonrasib produced median overall survival of 13.2 months versus 6.7 months with chemotherapy in the overall trial population; hazard ratio 0.40, p<0.0001. This was a randomized comparison of survival, a stronger validation than uncontrolled tumor-response data.
  • May 6: management discussed the implications for earlier pancreatic-cancer lines, lung cancer and the wider RAS(ON) portfolio. Its R&D discussion explicitly linked the result to increased confidence in the platform. Those additional indications still required their own trials.

My interpretation: The most plausible shift was from a promising RAS inhibitor to a potentially major oncology business with hard survival evidence, an approaching filing and several expansion opportunities. A single successful asset could also increase confidence in the discovery approach. A higher stock price could coexist with a more attractive risk-adjusted opportunity if success probability and the scope of the franchise rose enough.

Still unresolved: 13Fs do not identify whether every Q2 purchase followed April 13; some could have occurred in the first twelve days of the quarter. First-line and lung-cancer success could not be assumed from this result. The eventual approval and later 2026 results must not be used to explain the Q2 decision.

Confidence: Strong clinical event/quarter alignment; exact purchase dates and Darwin’s valuation unknown.

Sources: April 13 pivotal disclosure; February 25, 2026 transcript (source note); May 6, 2026 transcript (source note).

Ambrx (AMAM)

Observed ownership: 7.584m ADSs at Q4 2022 → 11.305m at Q1 2023 → 16.689m at Q2 2023. The March 8 13D identifies 3.615m ADSs bought through the issuer’s ATM on March 6, accounting for approximately 97% of the Q1 net increase. Another 5.384m ADS-equivalent units were bought through the $75m offering that closed June 27.

Public evidence available then:

  • October 18, 2022: the company reprioritized its pipeline around earlier-stage antibody-drug conjugates, including new lead asset ARX517, and planned cost reductions. The initial position therefore belonged to a restructuring/early-clinical story.
  • February 17, 2023: first ARX517 prostate-cancer data showed PSA reductions greater than 50% in three of three patients at the 2.0 mg/kg dose. Across 22 safety-evaluable patients, the company reported no grade 3-or-higher treatment-related adverse events. The efficacy cohort was extremely small and PSA was a biomarker, not survival.
  • March 1: partner-run ARX788 Phase 3 data in HER2-positive breast cancer met its interim primary PFS endpoint. This was a separate asset and tumor type, not direct confirmation of ARX517 efficacy.
  • March 6: Darwin made the documented 3.615m-unit purchase, after both disclosures. On May 23 it agreed the next investment, at $13.93 per ADS-equivalent unit, completed June 27. The March 13D disclosed $47.193m cost for the 11.305m-unit stake, an average of about $4.17 per unit; the new commitment was made at a much higher price.

My interpretation: This looks like recognition of a promising engineered ADC approach inside a company that had recently reset its strategy, followed by financing the development work needed to establish it. The stable linker/site-specific conjugation thesis mattered only if it produced human antitumor activity without losing the therapeutic window. The precise transaction dates make this the clearest example of paying more after new evidence.

Still unresolved: Three patients are not robust efficacy proof. Durability, dose expansion, toxicity at higher exposure and competitiveness against other PSMA approaches remained unresolved. The later J&J purchase does not establish that Darwin anticipated an acquisition.

Confidence: High on transaction sequencing and financing participation; scientific/valuation motivation remains inference.

Sources: October 2022 reprioritization; February 17 ARX517 data; March 1 ARX788 result; March 8 Darwin 13D; May 25 Darwin commitment; June 28 Darwin closing disclosure.

Cidara (CDTX)

Observed ownership: 768,424 shares at Q2 2025 → 997,196 at Q3 (+29.8%); unchanged at Q4. The Q3 addition followed the June Phase 2b readout.

Public evidence available then:

  • June 23, 2025: NAVIGATE reported positive results in a 5,041-participant randomized trial. A single 450 mg dose of CD388 provided 76.1% prevention efficacy against protocol-defined symptomatic influenza over 24 weeks versus placebo; lower doses also succeeded.
  • June 24: a $350m base offering priced at $44, improving the ability to fund the next trial. Public offering timing does not prove Darwin participated in it.
  • September 24: after its FDA meeting, the company outlined a single Phase 3 study, expanded eligibility and a start accelerated by six months. It said the contemplated US eligible population increased from approximately 50m to well over 100m and existing cash could fund the pivotal program. These were company plans and population estimates, not approval or a guaranteed addressable market.

My interpretation: A long-acting, non-vaccine influenza preventive had moved beyond a small proof-of-concept study, with a regulatory plan that could shorten the route to market and broaden the population. The economic attraction was protection through a flu season, particularly where vaccine response can be inadequate.

Still unresolved: NAVIGATE involved unvaccinated healthy participants. The highest-dose comparison had 8 protocol-defined cases versus 33 on placebo, with a 49.3%–89.9% confidence interval for prevention efficacy; event counts were much smaller than total enrollment. Replicating efficacy and safety in older, high-risk or immunocompromised patients remained essential. The September meeting cannot explain purchases made earlier in Q3. The subsequent Merck transaction was not known during the build.

Confidence: High that the addition followed Phase 2b evidence; timing relative to September FDA feedback unknown.

Sources: June 23 NAVIGATE presentation; August 7 clinical update; June 24 financing terms; September 24 FDA pathway update.

Verona (VRNA)

Observed ownership: 810,449 ADSs at Q4 2024 → 3.923m at Q1 2025 (+384%); 4.130m at Q2. This was a commercial scale-up, not a pre-approval binary bet.

Public evidence available then:

  • Ohtuvayre was approved June 26, 2024 and commercially available in August. The November 4 update reported $5.6m Q3 sales and said October sales already exceeded Q3.
  • January 7, 2025: preliminary Q4 sales were approximately $36m; more than 3,500 prescribers and 16,000 filled prescriptions in 2024, about one-third refills. The company reported over 35% monthly filled-prescription growth in Q4 and approximately two weeks of pharmacy inventory.
  • February 27: finalized Q4 sales were $36.6m. Prescriptions through February already exceeded all of Q4, prescribers exceeded 4,600, and about 55% of the company’s Tier 1 healthcare-professional targets had prescribed. A product-specific reimbursement J-code became effective January 1.

My interpretation: The remaining controversy was commercial adoption: would physicians add a new nebulized COPD treatment, would patients refill it, and would reimbursement support use? The early numbers provided evidence on all three. Reported limited channel inventory and refills helped distinguish patient use from a one-time initial stocking effect.

Still unresolved: Early launch results still needed to translate into persistent treatment, payer access, sustainable net pricing and broader adoption. Exact buy dates are unavailable. Merck’s later acquisition was not evidence available in Q1.

Confidence: High that ramping coincided with improving observed launch demand; inferred valuation interpretation.

Sources: November 4 early launch update; January 7 launch metrics; February 27 launch and reimbursement update.

Vaxcyte (PCVX)

Observed ownership: 579,959 shares at Q4 2023 → 2.751m at Q1 2024 (+374%). This increase preceded the VAX-31 readout expected in Q3 2024.

Public evidence available then:

  • By November 2023 the company had positive VAX-24 adult Phase 2 evidence, an FDA end-of-Phase-2 meeting and clearance to begin the broader VAX-31 trial. Its earlier studies reported robust immune responses across 24 serotypes and safety similar to PCV20.
  • January 4, 2024: VAX-31 moved into Phase 2 after independent Phase 1 safety review; the clinical update described VAX-24 as approaching Phase 3 and outlined the regulatory path.
  • February 27: the company said FDA discussions supported an immunogenicity-based licensure program without a separate efficacy study. It had $1.2bn of year-end cash/securities plus $816.5m net proceeds from the recent offering. Manufacturing rights from Sutro and the expanded Lonza relationship addressed important production dependencies.

My interpretation: The bet was that a clinically supported conjugation approach could add serotype coverage while preserving immune responses, challenging an established vaccine franchise. The company had a credible regulatory comparison and capital/manufacturing arrangements to execute it. This was extrapolation from earlier human validation, not waiting for the next trial to succeed.

Still unresolved: VAX-31 immunogenicity, added-serotype interference, reproducible commercial manufacturing and eventual pediatric efficacy/immunogenicity were not settled. Later September data cannot be used as an explanation for the Q1 ramp. Cross-trial or immune-response comparisons do not prove superior clinical outcomes.

Confidence: High that the major build was before the next readout; inferred platform/production thesis.

Sources: November 2023 clinical/regulatory update; January 4, 2024 clinical update; February 27 regulatory, capital and manufacturing update.

Acceleron (XLRN)

Observed ownership: Already 938,490 shares in the first Q4 2020 filing; 1.505m at Q1 2021, 1.760m at Q2 and 2m at Q3. The original investment date is unobservable.

Public evidence available then:

  • The PULSAR Phase 2 trial had shown improvements in pulmonary vascular resistance and six-minute walk distance when sotatercept was added to background PAH therapies.
  • November 2020: echocardiographic data supported improvements in right-heart function and coupling to the pulmonary circulation. This helped support the possibility of changing vascular disease biology, rather than only adding another vasodilator.
  • December 2020: the registrational STELLAR trial began. By the February 25, 2021 update the company had $857.5m cash and securities, existing REBLOZYL royalties and plans for additional PAH populations. May 2021 extension data provided further follow-up while shares continued to increase.

My interpretation: The potential was a differentiated treatment used on top of established PAH therapy, with meaningful physiological and functional human evidence and financing for pivotal work. It offered the prospect of becoming part of standard treatment across the disease, rather than competing only for a narrow late-line niche.

Still unresolved: The pivotal STELLAR result and later regulatory approval were years away during the first build. Phase 2 and open-label follow-up could not establish pivotal success. Merck’s later purchase is not proof of the original rationale.

Confidence: High on evidence available before the ramp; first-entry timing and internal rationale unknown.

Sources: November 2020 PULSAR cardiac data; February 2021 phase-transition and financial update; May 2021 PULSAR extension.

Belite Bio (BLTE)

Observed ownership: First 13F: 3.028m ADSs in Q4 2025, $486.9m. A December 10 13G reports 2.617m ordinary shares, a December 3 event date and 7% ownership. It therefore documents substantial ownership just after the December 1 result, though it does not date every purchase. Subsequent additions were small.

Public evidence available then:

  • December 1, 2025: DRAGON met its prespecified primary endpoint in 104 adolescents with Stargardt disease. Tinlarebant reduced retinal-lesion growth by 36% versus placebo, p=0.0033. The company planned an NDA in H1 2026.
  • The company explicitly said visual-acuity change over 24 months was minimal in both arms. The reported benefit was slowing anatomical disease progression; a demonstrated improvement in vision should not be claimed.
  • A $350m base offering was priced on December 1, following the data announcement. A separate geographic-atrophy trial offered another opportunity, but its outcome could not be inferred from Stargardt data.

My interpretation: A large position appeared when an oral drug for a disease without an approved therapy gained pivotal evidence and a potential filing path. The broader retinal opportunity could add value, but the investable core was the Stargardt result.

Still unresolved: Regulatory acceptance of the endpoint, clinical meaningfulness over time, vision outcomes and the independent geographic-atrophy trial remained material risks. Size is not proof the investment has worked.

Confidence: Good event/ownership timing from the 13G; not proof all units were bought after data.

Sources: December 1 DRAGON results; December 1 financing terms; Darwin December 10 13G.

Abivax (ABVX)

Observed ownership: First 13F: 3.165m ADSs at Q3 2025, $263.7m. Subsequent count growth to Q2 2026 was only 14.4%, so the initial entry was the principal commitment.

Public evidence available then:

  • July 22, 2025: both ABTECT induction trials succeeded at the 50 mg obefazimod dose in ulcerative colitis. Pooled placebo-adjusted clinical remission at eight weeks was 16.4 percentage points; the individual differences were 19.3 and 13.4 points.
  • The company reported favorable tolerability with no new safety signals and success on key secondary endpoints. Maintenance results were still expected in Q2 2026; the stated NDA plan depended on those results.

My interpretation: An oral drug with a distinct immune-regulatory mechanism had reproduced induction benefit in two large trials in an established, commercially important disease. The opportunity was a possible new treatment option with a broad clinical position, while durable benefit and the full regulatory package were still pending.

Still unresolved: The induction result did not establish maintenance efficacy or superiority to every competing IBD drug. The Q3 holding could include purchases before July 22; no precise trade dates were found.

Confidence: Strong quarter/event coincidence; execution timing and thesis are inferred.

Sources: July 22 two-trial induction results; September 8 financial/clinical update.

Roivant (ROIV)

Observed ownership: First 13F: 6.797m shares at Q1 2026; 6.747m at Q2. This is an initial allocation, not an observed scale-up after entry.

Public evidence available then:

  • December 2025 investor day outlined multiple potential launches, NDA/BLA filings and pivotal readouts over the following three years.
  • February 6, 2026: brepocitinib reported positive Phase 2 cutaneous-sarcoidosis results. March 3: FDA accepted its dermatomyositis NDA with priority review, supported by Phase 3 VALOR.
  • Also March 3: Genevant and Arbutus announced a Moderna settlement of $950m upfront plus a contingent $1.3bn. These are settlement-party amounts, not cash wholly attributable to Roivant.

My interpretation: This is more consistent with assessing several approaching clinical/commercial assets alongside financial resources and contingent value than with one binary readout. Brepocitinib’s regulatory progress made one path to a commercial business more concrete.

Still unresolved: The allocation might have preceded some March announcements. Ownership economics, contingent settlement proceeds and asset-specific risks require separate valuation. No later share-count increase supports calling this a ramp.

Confidence: Multiple plausible contemporaneous drivers; lower confidence in identifying one decisive cause.

Sources: December 2025 investor day; February 6 clinical update; March 3 priority review; March 3 settlement disclosure.

Other large positions: where the pattern changes

Intellia, Q2 2021: the first $301m position coincided with the June 26 NTLA-2001 announcement: the first in-vivo CRISPR clinical data, including mean TTR reduction of 87% at the higher studied dose and early safety in only six patients. The possible platform implication was large; the evidence was still a short-term biomarker in a tiny trial. Shares were reduced in subsequent quarters. This is a useful counterexample to the idea that every large position followed late-stage proof, and a reminder that a technology milestone is not equivalent to an established clinical/commercial franchise. June 2021 issuer release.

TG Therapeutics, Q1 2023: the 10.451m-share first appearance followed the December 28, 2022 approval of BRIUMVI, an anti-CD20 MS treatment with a one-hour maintenance infusion, and coincided with its launch. This fits a transition from clinical risk to adoption risk. There was no subsequent continuous build: Darwin reduced shares, exited, and later re-entered. Approval; February 2023 launch update.

Cytokinetics, Q2 2024: the 4.576m-share reappearance coincided with fuller positive SEQUOIA-HCM data for aficamten and preparation of regulatory submissions. It was absent in Q1, so this is a new holding spell, not a continuously compounded build from its Q4 2023 stake. The commercial question was a differentiated entrant into an existing HCM treatment market. May 13, 2024 primary results.

Pfizer, Q4 2021: a $454.6m single-quarter position overlapped the November 5 strong PAXLOVID efficacy disclosure and December authorization, on top of substantial vaccine revenue. A major incremental product opportunity is a plausible explanation; the record cannot isolate it from other reasons for owning Pfizer. This was not a speculative small-biotech development bet. November 5 antiviral result; authorization.

AstraZeneca, H1 2022: the count rose from 0.512m ADRs at Q4 2021 to 1.662m and then 2.849m. The contemporary opportunity set included expanding Enhertu evidence, including the February 21 DESTINY-Breast04 topline result in HER2-low breast cancer, plus a diversified portfolio and the Alexion integration. That is a plausible extension-of-franchise thesis, but assigning the entire position to Enhertu would overclaim. February 21, 2022 issuer release.

The comparison with Baker is clearest in Revolution

Baker's material Revolution build occurred in 2023–Q1 2024 as early RAS(ON) human activity emerged; Darwin's largest increase came in Q2 2026, the randomized survival-readout quarter. The underlying franchise opportunity was similar, but the scientific risk being accepted was different. This is one concrete comparison, not proof that either manager always invests at one development stage. Baker build study; Darwin ownership history.

Questions that would reproduce the analysis, rather than merely copy a 13F

The useful question is not simply whether a trial succeeded. Ask which uncertainty was reduced, by how much, and whether the remaining opportunity is large relative to the current enterprise value. The following are my reconstructed diligence questions, not quotes or a known Darwin checklist.

Question What to examine Case where it matters most
Is the evidence robust enough to change the expected outcome? Randomization, comparator, sample size, endpoint hierarchy, missing data, subgroup consistency, effect size and confidence interval Revolution survival; Insmed exacerbations; the much weaker three-patient Ambrx cohort
Does it improve patients’ lives in a way physicians will value? Clinical outcome versus biomarker; durability; safety and tolerability at intended exposure Belite anatomy versus vision; Intellia TTR reduction versus outcomes
Could this be routinely used in a sizable population? Eligibility, treatment line, add-on versus replacement, route, provider workflow, reimbursement Insmed, Acceleron, Verona
Is the next step executable? FDA alignment, trial design, enrollment, CMC, manufacturing rights and cash runway Vaxcyte; Cidara; directly funded Ambrx
What portion of future value remains unrecognized? Independently estimated probability of approval, eligible patients, penetration, net price, duration, margins, dilution and time to cash flow Every case; public sources do not provide Darwin’s model
Is early commercial activity real and repeatable? Refills, prescriber depth, inventory, paid access, net revenue per patient and persistence Verona
What would invalidate the thesis? Failure on the remaining endpoint, late safety, reimbursement restrictions, manufacturing delays, or adoption below the underwriting case Abivax maintenance; Cidara high-risk trial; Belite clinical meaning

A useful conceptual expression is expected asset value = probability-weighted future cash flows, less remaining development costs and financing needs. A positive trial can raise that value even after a large share-price jump; it can also be fully priced immediately. Nothing in a 13F establishes which was true.

Timing controls and limitations

  • No primary source in a case is dated after that case’s analyzed build endpoint. Later takeovers and approvals are excluded from the explanation of earlier decisions.

  • March 6 and June 27, 2023 Ambrx transactions are specifically disclosed. Insmed’s August 2024 and Belite’s December 2025 13Gs narrow the observation dates. Other cases generally remain quarter-end intervals.

  • No conclusion is drawn that one financing supplied all purchased shares, except the specifically disclosed Ambrx transactions. Financing capacity is separate from a manager’s participation.

  • No claim is made that this selected sample measures strategy effectiveness. Several large holdings failed to sustain value; successful investments are easier to narrate in retrospect.

  • Neither a high 13F weight nor gross share additions disclose net risk, hedges, cash, private holdings, fund flows or exact NAV allocations.

  • Full acquisition motive, internal forecasts, diligence calls and execution prices remain unknown. The causal interpretation should be tested against those records if they become available.

Evidence catalogue: structured cases; 413-document source manifest.

As of November 7, 2026. CIK 1839209. 23 quarterly filings, Q4 2020–Q2 2026. The requested ten-year lookback contains no earlier Darwin 13F records under this manager; holdings in its first filing may have been bought earlier. Latest holdings are June 30, 2026 observations, filed August 14, not November holdings. 2020 Q4 13F; 2026 Q2 13F.

Insmed is the dominant observable dollar winner and the largest position Darwin has reported. Revolution Medicines is the largest new commitment and latest holding. Ambrx is the strongest takeover case with disclosed purchase-cost evidence; Cidara and Verona are the next clear large appreciation cases.

I reviewed all 149 reported rows, 68 original CUSIPs and 67 security lineages, joining Ambrx’s documented one-for-one ADS conversion. All 23 original SEC information tables are archived. Share counts and identifiers agree with the provider; 21 tables agree fully before corrections. Two 2022 AstraZeneca values needed a 1,000x normalization correction from the raw XML. After that correction, every holdings total reconciles to its cover page. No 13F amendments were returned in the queried history. The source-linked workbook contains every position and all 52 material appearance/increase events.

Exact realized profits generally cannot be reconstructed from 13Fs. The filing-mark appreciation proxy below sums average opening/closing shares multiplied by the change in reported value per share, only across consecutive positive quarter-end holdings. It excludes first-entry and complete-exit quarters, dividends, financing costs and intraperiod trades. This is a screen for likely dollar winners, not audited fund P&L. I also checked all 32 mapped securities with usable intervals against independent exchange closes.

Biggest observable winners and the main commitments

Investment Evidence of appreciation First reported Decisive build Peak reported position
INSMED INC (INSM) ~$1.1bn captured; $1.050bn filing marks / $1.146bn exchange closes Q2 2024 3.54m → 10.50m in Q3 2024; 20.93m by Q4 2025 $3.644bn, 2025 Q4
REVOLUTION MEDICINES INC (RVMD) ~$0.6bn one-interval proxy; highly timing-sensitive Q1 2026 2.21m → 10.63m in Q2 2026 (+381%) $2.048bn, 2026 Q2
AMBRX BIOPHARMA INC (AMAM) $345.1m above disclosed cost if the final stake was held to $28 closing; 3.82x proceeds/cost Q4 2022 7.58m → 11.30m → 16.69m in Q4 2022–Q2 2023 $274.7m, 2023 Q2
CIDARA THERAPEUTICS INC (CDTX) $165.6m captured before final tender quarter Q2 2025 0.768m → 0.997m in Q3 2025 (+29.8%) $220.2m, 2025 Q4
VERONA PHARMA PLC (VRNA) $163.8m captured before exit quarter Q4 2024 0.810m → 3.923m in Q1 2025 (+384%) $387.4m, 2025 Q2
VAXCYTE INC (PCVX) $110.4m captured; full-exit quarter omitted Q4 2023 0.580m → 2.751m in Q1 2024 (+374%) $251.2m, 2024 Q3
ACCELERON PHARMA INC (XLRN) $80.5m captured; ~$96.3m including conditional closing uplift Already Q4 2020 0.938m → 1.505m in Q1 2021; 2.0m by Q3 2021 $344.2m, 2021 Q3

The Ambrx number is a cost-based, explicitly conditional takeover scenario; all other estimates are inventory-based appreciation screens. They must not be summed into a fund return. RVMD’s rapid buying makes its estimate particularly uncertain. TG Therapeutics mechanically produces $96.7m from one interval, but two full exits are missing, so it is not presented as a confirmed leading lifetime winner.

Largest positions ever reported

Peak value and peak weight can occur in different quarters. Weights use the reported 13F book, not fund NAV.

Rank Investment Peak dollar value Quarter Maximum 13F weight First public quarter
1 INSMED INC (INSM) $3.644bn 2025 Q4 84.8% (2024 Q4) 2024 Q2
2 REVOLUTION MEDICINES INC (RVMD) $2.048bn 2026 Q2 54.5% (2026 Q2) 2026 Q1
3 BELITE BIO INC (BLTE) $486.9m 2025 Q4 12.1% (2026 Q2) 2025 Q4
4 PFIZER INC (PFE) $454.6m 2021 Q4 69.4% (2021 Q4) 2021 Q4
5 ABIVAX SA (ABVX) $439.7m 2025 Q4 9.3% (2026 Q1) 2025 Q3
6 VERONA PHARMA PLC (VRNA) $387.4m 2025 Q2 16.8% (2025 Q1) 2024 Q4
7 ACCELERON PHARMA INC (XLRN) $344.2m 2021 Q3 63.4% (2021 Q3) 2020 Q4
8 UNITED THERAPEUTICS CORP DEL (UTHR) $317.6m 2025 Q3 8.8% (2025 Q3) 2025 Q3
9 INTELLIA THERAPEUTICS INC (NTLA) $301.1m 2021 Q2 48.6% (2021 Q2) 2021 Q2
10 AMBRX BIOPHARMA INC (AMAM) $274.7m 2023 Q2 67.5% (2023 Q3) 2022 Q4
11 VAXCYTE INC (PCVX) $251.2m 2024 Q3 25.0% (2024 Q1) 2023 Q4
12 CYTOKINETICS INC (CYTK) $246.1m 2024 Q2 28.6% (2024 Q2) 2023 Q4
13 ROIVANT SCIENCES LTD (ROIV) $234.3m 2026 Q2 6.2% (2026 Q2) 2026 Q1
14 TG THERAPEUTICS INC (TGTX) $230.5m 2023 Q2 43.0% (2023 Q1) 2023 Q1
15 CIDARA THERAPEUTICS INC (CDTX) $220.2m 2025 Q4 4.5% (2025 Q4) 2025 Q2
16 ASTRAZENECA PLC (AZN) $188.2m 2022 Q2 100.0% (2022 Q1) 2021 Q4
17 BRIDGEBIO PHARMA INC (BBIO) $128.8m 2021 Q1 25.2% (2021 Q1) 2020 Q4
18 WAVE LIFE SCIENCES LTD (WVE) $125.2m 2025 Q4 2.5% (2025 Q4) 2025 Q4
19 FATE THERAPEUTICS INC (FATE) $113.0m 2021 Q1 24.2% (2020 Q4) 2020 Q4
20 ARGENX SE (ARGX) $112.8m 2022 Q4 70.2% (2022 Q4) 2022 Q4

Pfizer, United Therapeutics and Wave each appear in only one quarter. Their large sizes are observable; their investment profits are not. Belite’s captured price contribution is negative despite its position size.

Latest disclosed positions and when they were built

The Q2 2026 filing totals $3.760bn across five holdings. The top two account for 72.4%. 2026 Q2 13F.

Investment Value Weight First appearance Q1 2026 units Q2 2026 units Q/Q count change
RVMD $2.048bn 54.45% 2026 Q1 2,211,018 10,629,822 +380.8%
INSM $673.6m 17.91% 2024 Q2 16,805,184 6,431,163 -61.7%
BLTE $456.6m 12.14% 2025 Q4 3,057,412 3,077,219 +0.6%
ABVX $348.2m 9.26% 2025 Q3 3,468,657 3,621,583 +4.4%
ROIV $234.3m 6.23% 2026 Q1 6,797,300 6,747,300 -0.7%

The major 2026 change is a reduction in Insmed alongside a large Revolution build. Insmed’s share count fell 69.3% from its Q4 2025 peak, while RVMD rose 380.8% in Q2 2026. This shows an exposure shift; 13Fs do not establish that one sale directly financed the other purchase.

Entry and scaling case studies

Reported units are common shares or ADSs/ADRs as applicable. A first appearance identifies a quarter, not an execution date. Material changes in share count need not all be open-market purchases.

INSMED INC (INSM)

Entry: Q2 2024: 3,541,095 shares, $237.1m and 27.6% of reported value.

Build: Q3 2024: 10,497,277 shares (+196.4%); Q4 2024: 12,960,538 (+23.5%); Q1 2025: 15,397,975 (+18.8%); Q2 2025: 19,344,621 (+25.6%); Q3 2025: 20,457,445; Q4 2025: 20,933,277. The first six months tripled the position; accumulation continued through 2025.

The dominant observable dollar winner. The filing-mark appreciation proxy is $2.007bn through Q4 2025, followed by −$956.3m in the two observed 2026 intervals, leaving $1.050bn. Using independent exchange closes gives $1.146bn. Peak reported value was $3.644bn in Q4 2025; peak 13F weight was 84.8% in Q4 2024. Shares fell to 16,805,184 in Q1 2026 and 6,431,163 in Q2 2026: down 69.3% from the peak count.

Limit: Entry-quarter upside is omitted. Partial-sale timing is unknown; the $1.05–1.15bn checks are not actual profit. Prices implied by some filed values differ from exchange closes.

Sources: 2024 Q2 13F; 2024 Q3 13F; 2024 Q4 13F; 2025 Q1 13F; 2025 Q2 13F; 2025 Q3 13F; 2025 Q4 13F; 2026 Q1 13F; 2026 Q2 13F.

REVOLUTION MEDICINES INC (RVMD)

Entry: Q1 2026: 2,211,018 shares, $205.0m and 5.4% of the reported book.

Build: Q2 2026: 10,629,822 shares, a 380.8% increase. Added shares valued at the filed quarter-end mark equate to $1.622bn, which is not their cash purchase cost.

The latest dominant holding: $2.048bn and 54.5% of reported value. One consecutive-quarter interval produces $641.5m using filing-implied marks, or $578.0m using exchange closes. This is the largest new position and a strong observed price move, but the result is unusually sensitive to when the 8.42m additional shares were bought.

Limit: One interval only. At the filing-implied price change, using opening versus closing shares gives $220.9m versus $1,062.0m. Those are inventory sensitivity cases, not statistical bounds on actual profit.

Sources: 2026 Q1 13F; 2026 Q2 13F.

AMBRX BIOPHARMA INC (AMAM)

Entry: Q4 2022: 7,584,489 ADSs, $17.2m and 10.7% of the reported book.

Build: Q1 2023: 11,304,573 ADSs (+49.0%); Q2 2023: 16,688,636 (+47.6%). The 5,384,063-unit second increase exactly matches the $75m private placement signed May 23 and closed June 27, 2023 at $13.93 per ADS. The count remained 16,688,636 through Q4 2023; October 2023 converted each ADS into one common share.

A major takeover winner with disclosed cost evidence. The June 28, 2023 Schedule 13D reports total purchase cost of $122,193,074.92 for the 16,688,636 ADS-equivalent position. The same count appears in the final Q4 2023 13F. At J&J’s March 7, 2024 cash closing price of $28, holding all those shares to closing would produce $467,281,808 of gross proceeds, $345,088,733 above disclosed purchase cost, and 3.82x gross proceeds/cost. Closing inventory has not been independently confirmed, so this remains a hold-to-close scenario. It is separate from the generic quarterly proxy, which captures $131.3m before the takeover quarter.

Limit: Use the disclosed cost for the takeover scenario. The $28/$2.27 = 12.33x stock-price comparison is not Darwin’s investment multiple.

Sources: 2022 Q4 13F; 2023 Q1 13F; 2023 Q2 13F; 2023 Q3 13F; 2023 Q4 13F. Darwin June 28, 2023 Schedule 13D/A; Issuer placement disclosure; Nasdaq one-for-one ADS conversion; March 7, 2024 closing 8-K.

CIDARA THERAPEUTICS INC (CDTX)

Entry: Q2 2025: 768,424 shares, $38.0m and 1.6% of reported value.

Build: Q3 2025: 997,196 shares (+29.8%); unchanged in Q4 2025.

The quarterly proxy captures $165.6m ($166.3m with exchange closes). The last reported stake was $220.2m. Merck completed its tender offer on January 7, 2026 at $221.50 per share; if the final reported inventory was retained, gross consideration would be $220.879m, only $0.698m above the final 13F mark. Most of the observable appreciation is therefore already captured. Shares were absent in Q1 2026.

Limit: The $221.50 takeout price is 4.48x the first $49.45 filing-implied mark, not a confirmed fund MOIC.

Sources: 2025 Q2 13F; 2025 Q3 13F; 2025 Q4 13F. Merck tender-completion announcement.

VERONA PHARMA PLC (VRNA)

Entry: Q4 2024: 810,449 ADSs, $37.6m and 3.6% of reported value.

Build: Q1 2025: 3,923,204 ADSs (+384.1%); Q2 2025: 4,129,618 (+5.3%). The decisive commitment was Q1 2025.

Reported value reached $387.4m and 16.3% in Q2 2025. The captured proxy is $163.8m ($165.5m with exchange closes). The position disappeared in Q3 2025. Merck’s acquisition closed October 7, 2025 at $107 per ADS, after Darwin’s last reported holding and after the first quarter in which it was absent.

Limit: Do not credit the $107 closing price to Darwin: its Q3 disappearance places the observable exit before closing. Exit-quarter gains or losses are unmeasured.

Sources: 2024 Q4 13F; 2025 Q1 13F; 2025 Q2 13F. Merck October 7, 2025 closing.

VAXCYTE INC (PCVX)

Entry: Q4 2023: 579,959 shares, $36.4m and 7.1% of reported value.

Build: Q1 2024: 2,750,804 shares (+374.3%), reaching $187.9m and 25.0%. Then 2,080,946 in Q2 2024 and 2,198,187 in Q3 2024.

Peak value was $251.2m in Q3 2024. Captured appreciation is $110.4m ($109.5m using exchange closes). It disappeared in Q4 2024.

Limit: The complete-exit quarter is omitted; $110m is not verified lifetime profit.

Sources: 2023 Q4 13F; 2024 Q1 13F; 2024 Q2 13F; 2024 Q3 13F.

ACCELERON PHARMA INC (XLRN)

Entry: Already held in the first available filing, Q4 2020: 938,490 shares and $120.1m. The actual investment may predate the public record.

Build: Q1 2021: 1,505,012 shares (+60.4%); Q2 2021: 1,760,346 (+17.0%); Q3 2021: 2,000,000 (+13.6%).

The last reported stake was $344.2m, or 63.4% of the book, in Q3 2021. Merck announced completed acquisition on November 22, 2021 following its $180-per-share tender. Holding the final 2m shares to closing would imply $360m gross proceeds and $15.8m beyond the last mark. Adding that conditional uplift to the $80.5m consecutive-quarter proxy gives $96.3m. Earlier pre-filing gains remain unmeasured.

Limit: Opening holdings are left-censored; the $96.3m scenario is not lifetime profit or confirmed sale proceeds.

Sources: 2020 Q4 13F; 2021 Q1 13F; 2021 Q2 13F; 2021 Q3 13F. Merck $180 tender completion; Merck acquisition completion.

TG THERAPEUTICS INC (TGTX)

Entry: Q1 2023: 10,451,241 shares, $157.2m and 43.0% of the reported book.

Build: The initial filing already showed the major stake. Shares fell to 9,278,439 in Q2 2023; it was absent in Q3 2023, reappeared at 4,046,598 in Q4 2023 and was absent again in Q1 2024.

The sole consecutive-quarter interval captures $96.7m and peak reported value of $230.5m. That leaves out both complete-exit quarters. The two spells must not be treated as continuous ownership.

Limit: A positive captured interval is insufficient to establish a major lifetime winner. Rank TG below the better-evidenced cases, despite its mechanical screen result.

Sources: 2023 Q1 13F; 2023 Q2 13F; 2023 Q4 13F.

BELITE BIO INC (BLTE)

Entry: Q4 2025: 3,027,704 ADSs, $486.9m and 9.9% of reported value.

Build: Q1 2026: 3,057,412 ADSs; Q2 2026: 3,077,219. Only a 1.6% increase in count from first appearance to latest filing.

Darwin’s third-largest historical peak dollar position and third-largest latest holding. Latest reported value is $456.6m, or 12.1%. The observed price contribution is negative ($37.9m), so size does not establish a winner.

Limit: The substantial commitment was present at first appearance; subsequent weight growth mainly reflects changes in the rest of the reported portfolio.

Sources: 2025 Q4 13F; 2026 Q1 13F; 2026 Q2 13F.

ABIVAX SA (ABVX)

Entry: Q3 2025: 3,164,501 ADSs, $263.7m and 7.3% of reported value.

Build: Q4 2025: 3,178,501 ADSs; Q1 2026: 3,468,657; Q2 2026: 3,621,583. Total count increased 14.4% from first appearance.

Peak reported value was $439.7m in Q4 2025; latest is $348.2m and 9.3%. The stock rose sharply in the first observed follow-on quarter, then gave back much of that gain. Net captured appreciation is $33.1m using filed marks.

Limit: A large position, but much smaller captured dollar gains than Insmed, Ambrx or the other leading cases.

Sources: 2025 Q3 13F; 2025 Q4 13F; 2026 Q1 13F; 2026 Q2 13F.

ROIVANT SCIENCES LTD (ROIV)

Entry: Q1 2026: 6,797,300 shares, $179.5m and 4.8% of reported value.

Build: Q2 2026: 6,747,300 shares, a 0.7% reduction. No observed scale-up after the initial appearance.

Latest reported value rose to $234.3m and 6.2% through price appreciation. The one-interval proxy is $56.3m ($52.1m using exchange closes).

Limit: Position-value growth should not be described as accumulation when the share count fell.

Sources: 2026 Q1 13F; 2026 Q2 13F.

PFIZER INC (PFE)

Entry: Q4 2021: 7,697,762 shares, $454.6m and 69.4% of the reported book.

Build: Only one quarter-end observation; absent in Q1 2022.

Fourth-largest peak dollar holding in the available record. No adjacent positive observations exist to estimate appreciation.

Limit: A one-quarter appearance does not mean zero return. Entry and exit execution prices are unknown.

Sources: 2021 Q4 13F.

ASTRAZENECA PLC (AZN)

Entry: Q4 2021: 511,908 ADRs, $29.8m.

Build: Q1 2022: 1,661,684 ADRs (+224.6%); Q2 2022: 2,849,109 (+71.5%).

The only reported 13F holding in Q1 and Q2 2022, valued at $110.236m and $188.241m respectively. It was absent in Q3 2022. The raw SEC XML values were in thousands; the data provider failed to multiply these two observations by 1,000, which this report corrects.

Limit: 100% of the 13F book is not 100% of fund NAV. No inference of a cash-only fund or near-zero assets is justified.

Sources: 2021 Q4 13F; 2022 Q1 13F; 2022 Q2 13F.

INTELLIA THERAPEUTICS INC (NTLA)

Entry: Q2 2021: 1,859,926 shares, $301.1m and 48.6% of reported value.

Build: No subsequent scale-up: 752,024 shares in Q3 2021 and 605,587 in Q4 2021, then absent in Q1 2022.

A large initial commitment followed by reductions. Captured appreciation is negative $47.0m, although any gain before its first quarter-end appearance is omitted.

Limit: Do not classify a large first-quarter mark as a successful lifetime investment or use the subsequent negative proxy to prove an overall loss.

Sources: 2021 Q2 13F; 2021 Q3 13F; 2021 Q4 13F.

CYTOKINETICS INC (CYTK)

Entry: Q4 2023: 600,000 shares and $50.1m.

Build: Absent Q1 2024, then reappeared Q2 2024 with 4,575,558 shares, $246.1m and 28.6% of reported value. Absent again Q3 2024.

Two separated snapshots, not a demonstrated continuous 7.6x scale-up. The re-entry was economically large, but there is no consecutive positive quarter to support an appreciation estimate.

Limit: Reappearances are distinguished from increases in continuing positions.

Sources: 2023 Q4 13F; 2024 Q2 13F.

Portfolio evolution, quarter by quarter

Quarter Reported value Entries Largest holding Weight
2020 Q4 $358.4m 12 XLRN 33.5%
2021 Q1 $510.7m 12 XLRN 40.0%
2021 Q2 $619.9m 12 NTLA 48.6%
2021 Q3 $543.3m 12 XLRN 63.4%
2021 Q4 $654.6m 13 PFE 69.4%
2022 Q1 $110.2m 1 AZN 100.0%
2022 Q2 $188.2m 1 AZN 100.0%
2022 Q3 $66.4m 2 VTYX 73.7%
2022 Q4 $160.6m 4 ARGX 70.2%
2023 Q1 $365.6m 4 TGTX 43.0%
2023 Q2 $611.7m 3 AMAM 44.9%
2023 Q3 $284.2m 3 AMAM 67.5%
2023 Q4 $509.5m 8 AMAM 46.6%
2024 Q1 $751.2m 12 PCVX 25.0%
2024 Q2 $859.5m 9 CYTK 28.6%
2024 Q3 $1.230bn 5 INSM 62.3%
2024 Q4 $1.056bn 6 INSM 84.8%
2025 Q1 $1.463bn 3 INSM 82.1%
2025 Q2 $2.383bn 5 INSM 80.8%
2025 Q3 $3.598bn 5 INSM 80.5%
2025 Q4 $4.939bn 6 INSM 73.8%
2026 Q1 $3.771bn 6 INSM 68.3%
2026 Q2 $3.760bn 5 RVMD 54.5%

The sequence is highly concentrated: Acceleron/Intellia in 2021; Pfizer at year-end 2021; AstraZeneca alone in H1 2022; Ambrx/TG in 2023; Insmed dominating late 2024–2025; and Revolution in Q2 2026. Changes in total reported value combine investment performance, trading, flows and exposure outside 13F scope. They are not fund return calculations.

Data checks and interpretation

Two unit corrections: Q1 2022 AstraZeneca is $110,236,000 and Q2 2022 is $188,241,000. Their original XML values are 110,236 and 188,241 in the then-required thousands unit. The provider supplied them as dollars. Corrected values are used throughout the report and workbook; the unmodified provider responses are preserved in the archive. 2022 Q1 13F; 2022 Q2 13F.

Filed marks are not always exchange closes. For example, June 2026 RVMD value/share is $192.62 versus the independently sourced $187.28 close; March 2026 INSM is $153.32 versus $163.52. I preserve filed dollar values for position-size/weight reporting and show the market-price sensitivity separately. No conclusion about the reason for those differences is assumed. The full check is in the workbook and archived Massive daily-price responses.

Investment Filed-mark proxy Exchange-close proxy
INSM $1.050bn $1.146bn
RVMD $641.5m $578.0m
AMAM $131.3m $131.3m
CDTX $165.6m $166.3m
VRNA $163.8m $165.5m
PCVX $110.4m $109.5m
XLRN $80.5m $80.5m
TGTX $96.7m $96.7m

Exchange prices use the last trading close on or before each quarter-end, within five calendar days, unadjusted, from the existing local Massive price-data integration. Only the same consecutive holdings intervals are compared. Source request URLs and marks appear in Price checks; this does not supply missing entry/exit execution prices.

  • The entire available record has 23 quarterly observations, not ten years. Earlier private exposure and holdings before the initial filing remain unknown.

  • First-entry and complete-exit quarters are unmeasured. No measurable interval means not measurable, not a zero return. Re-entry spells are kept distinct.

  • The average-inventory method can overstate or understate appreciation when buying or selling occurs around price moves; RVMD is the clearest example. Inventory sensitivity endpoints are not confidence bounds.

  • The Ambrx ADS/common continuity is confirmed one-for-one. All other CUSIPs are separate security histories; no additional splitlike intervals were detected by the screen.

  • Private positions, shorts, cash, nonreportable assets and confidentially omitted positions are outside the visible record. 13F concentration is not NAV concentration.

  • Scaling events: a continuing share increase of at least 20% ending at $25m or more, or added shares worth at least $100m at the end mark; material first/reappearances at $25m or more are separately labeled. The initial filing’s holdings are labeled existing when first disclosed.

Complete security census

The workbook is the sortable version. “Not measurable” means no consecutive-quarter calculation was possible. This is not an issuer-level lifetime return ranking.

Security CUSIP lineage First observed Last observed Peak value Captured proxy
INSMED INC (INSM) 457669307 2024 Q2 2026 Q2 $3.644bn $1.050bn
REVOLUTION MEDICINES INC (RVMD) 76155X100 2026 Q1 2026 Q2 $2.048bn $641.5m
BELITE BIO INC (BLTE) 07782B104 2025 Q4 2026 Q2 $486.9m $-37.9m
PFIZER INC (PFE) 717081103 2021 Q4 2021 Q4 $454.6m Not measurable
ABIVAX SA (ABVX) 00370M103 2025 Q3 2026 Q2 $439.7m $33.1m
VERONA PHARMA PLC (VRNA) 925050106 2024 Q4 2025 Q2 $387.4m $163.8m
ACCELERON PHARMA INC (XLRN) 00434H108 2020 Q4 2021 Q3 $344.2m $80.5m
UNITED THERAPEUTICS CORP DEL (UTHR) 91307C102 2025 Q3 2025 Q3 $317.6m Not measurable
INTELLIA THERAPEUTICS INC (NTLA) 45826J105 2021 Q2 2021 Q4 $301.1m $-47.1m
AMBRX BIOPHARMA INC (AMAM) 641871108 2022 Q4 2023 Q4 $274.7m $131.3m
VAXCYTE INC (PCVX) 92243G108 2023 Q4 2024 Q3 $251.2m $110.4m
CYTOKINETICS INC (CYTK) 23282W605 2023 Q4 2024 Q2 $246.1m Not measurable
ROIVANT SCIENCES LTD (ROIV) G76279101 2026 Q1 2026 Q2 $234.3m $56.3m
TG THERAPEUTICS INC (TGTX) 88322Q108 2023 Q1 2023 Q4 $230.5m $96.7m
CIDARA THERAPEUTICS INC (CDTX) 171757206 2025 Q2 2025 Q4 $220.2m $165.6m
ASTRAZENECA PLC (AZN) 046353108 2021 Q4 2022 Q2 $188.2m $8.2m
BRIDGEBIO PHARMA INC (BBIO) 10806X102 2020 Q4 2021 Q3 $128.8m $-18.0m
WAVE LIFE SCIENCES LTD (WVE) Y95308105 2025 Q4 2025 Q4 $125.2m Not measurable
FATE THERAPEUTICS INC (FATE) 31189P102 2020 Q4 2021 Q4 $113.0m $-15.8m
ARGENX SE (ARGX) 04016X101 2022 Q4 2023 Q3 $112.8m $19.2m
NUVALENT INC (NUVL) 670703107 2023 Q4 2024 Q1 $107.9m $1.1m
GERON CORP (GERN) 374163103 2024 Q2 2024 Q4 $106.2m $-13.5m
KEROS THERAPEUTICS INC (KROS) 492327101 2021 Q1 2024 Q4 $95.1m $-49.3m
BIOHAVEN LTD (BHVN) G1110E107 2024 Q1 2024 Q1 $80.8m Not measurable
ALPINE IMMUNE SCIENCES INC (ALPN) 02083G100 2024 Q1 2024 Q1 $78.6m Not measurable
BEAM THERAPEUTICS INC (BEAM) 07373V105 2021 Q2 2024 Q1 $70.0m Not measurable
IMMUNOVANT INC (IMVT) 45258J102 2020 Q4 2023 Q3 $69.8m $-4.0m
MOONLAKE IMMUNOTHERAPEUTICS (MLTX) 61559X104 2023 Q4 2023 Q4 $62.8m Not measurable
JAZZ PHARMACEUTICALS PLC (JAZZ) G50871105 2024 Q4 2024 Q4 $59.7m Not measurable
MIRATI THERAPEUTICS INC (MRTX) 60468T105 2020 Q4 2020 Q4 $57.3m Not measurable
APOGEE THERAPEUTICS INC (APGE) 03770N101 2024 Q1 2024 Q1 $55.3m Not measurable
VENTYX BIOSCIENCES INC (VTYX) 92332V107 2022 Q3 2022 Q3 $48.9m Not measurable
BIONTECH SE (unmapped) 09075V102 2021 Q3 2021 Q4 $36.3m $-1.7m
RELAY THERAPEUTICS INC (RLAY) 75943R102 2021 Q1 2021 Q2 $27.1m $0.9m
INHIBRX INC (INBX) 45720L107 2020 Q4 2021 Q4 $25.9m $8.6m
XENCOR INC (XNCR) 98401F105 2024 Q1 2024 Q1 $24.6m Not measurable
UNIQURE NV (QURE) N90064101 2025 Q3 2025 Q3 $23.8m Not measurable
SUMMIT THERAPEUTICS INC (SMMT) 86627T108 2024 Q3 2024 Q3 $23.8m Not measurable
CAPRICOR THERAPEUTICS INC (CAPR) 14070B309 2025 Q4 2025 Q4 $23.2m Not measurable
MERUS N V (MRUS) N5749R100 2025 Q2 2025 Q2 $21.0m Not measurable
SAREPTA THERAPEUTICS INC (SRPT) 803607100 2020 Q4 2020 Q4 $19.6m Not measurable
SPYRE THERAPEUTICS INC (SYRE) 00773J202 2024 Q1 2024 Q2 $17.9m $-7.0m
KARUNA THERAPEUTICS INC (KRTX) 48576A100 2022 Q3 2022 Q3 $17.5m Not measurable
ALLOGENE THERAPEUTICS INC (ALLO) 019770106 2025 Q1 2025 Q2 $16.2m $-3.9m
CORBUS PHARMACEUTICALS HLDGS (CRBP) 21833P301 2024 Q2 2024 Q2 $14.3m Not measurable
ENANTA PHARMACEUTICALS INC (ENTA) 29251M106 2021 Q4 2021 Q4 $12.4m Not measurable
ELEVATION ONCOLOGY INC (ELEV) 28623U101 2024 Q1 2024 Q2 $12.0m $-5.6m
TOURMALINE BIO INC (TRML) 89157D105 2024 Q1 2024 Q1 $10.6m Not measurable
MERCK & CO INC (MRK) 58933Y105 2024 Q1 2024 Q1 $10.5m Not measurable
PROMETHEUS BIOSCIENCES INC (RXDX) 74349U108 2022 Q4 2022 Q4 $10.1m Not measurable
ARVINAS INC (ARVN) 04335A105 2020 Q4 2021 Q1 $9.3m $-1.7m
MACROGENICS INC (MGNX) 556099109 2021 Q1 2021 Q1 $9.1m Not measurable
AVIDITY BIOSCIENCES INC (RNA) 05370A108 2024 Q2 2024 Q2 $8.1m Not measurable
C4 THERAPEUTICS INC (CCCC) 12529R107 2020 Q4 2021 Q1 $7.6m $0.7m
SPRINGWORKS THERAPEUTICS INC (SWTX) 85205L107 2023 Q4 2023 Q4 $7.0m Not measurable
GENERATION BIO CO (GBIO) 37148K100 2020 Q4 2021 Q2 $6.2m $-0.2m
VERVE THERAPEUTICS INC (VERV) 92539P101 2021 Q2 2021 Q4 $6.2m $-1.1m
VIR BIOTECHNOLOGY INC (VIR) 92764N102 2021 Q3 2021 Q4 $6.1m $-0.2m
ESSA PHARMA INC (unmapped) 29668H708 2021 Q2 2021 Q2 $6.0m Not measurable
CHEMOCENTRYX INC (CCXI) 16383L106 2021 Q4 2021 Q4 $5.9m Not measurable
FULCRUM THERAPEUTICS INC (FULC) 359616109 2020 Q4 2021 Q4 $5.6m $-1.8m
ACLARIS THERAPEUTICS INC (ACRS) 00461U105 2021 Q2 2021 Q4 $4.4m $-0.6m
ADAGIO THERAPEUTICS INC (IVVD) 00534A102 2021 Q3 2021 Q3 $3.7m Not measurable
NURIX THERAPEUTICS INC (NRIX) 67080M103 2024 Q4 2024 Q4 $3.1m Not measurable
DIANTHUS THERAPEUTICS INC (DNTH) 252828108 2026 Q1 2026 Q1 $1.5m Not measurable
STOKE THERAPEUTICS INC (STOK) 86150R107 2020 Q4 2020 Q4 $0.4m Not measurable
AEROVATE THERAPEUTICS INC (AVTE) 008064107 2021 Q3 2021 Q3 $0.3m Not measurable

Deliverables

  • Workbook

  • Share-count timelines

  • Source archive and reproducible scripts: local research archive; public references are listed under Sources & files.

Sources & research files

Each clinical claim is tied to a dated source in the playbook. The ownership study includes filing links, the winner-proxy method and its limitations. The full holdings workbook is available below.

The workbook incorporates the two AstraZeneca value-unit corrections and the documented Ambrx security conversion.

The position histories

Darwin reported share-count timelines from the accompanying 13F study
Source: the validated quarterly ownership archive. Reported shares are not transaction dates or complete economic exposure. See the study for corporate-action adjustments.

Transcript source notes

The Revolution earnings transcripts were consulted in the research archive. They are not republished here. These public issuer releases provide the corresponding dated company updates; they do not reproduce the complete call or analyst Q&A.

February 25, 2026 issuer results release · May 6, 2026 issuer results release

The filing catalogue

The 413 archived filing documents and exhibits below are the retrieval catalogue. They include background context; the dated citations beside each case identify the evidence used for that historical build period.

413 of 413 archived documents