Siren, L.L.C.
CIK 2005245 · EDGAR ↗
- sum of disclosed values for 2026-03-31; 0 positions have no disclosed value and are left out of the sum, counted here rather than dropped
- $3.6B
- every reported holding for this filer and quarter, including ones with no disclosed value
- 102
- positions with no comparable holding in the prior quarter (kind new), 2026-03-31
- 19
- positions absent from this quarter's filing after being held last quarter (kind exit), 2026-03-31 — inferred from absence, not a sale record
- 32
Quarter-end snapshot, filed up to 45 days later — not current holdings. What a 13F covers ↓
Changes · Quarter ended 2026-03-31. Newest filing in this build: 2026-07-31. Per-row filing dates are on each receipt.
by shares · How classified ↗Period
| The reviewed ticker for the filed issuer name and share class, the same mapping the Reported positions table uses. Symbols are never inferred from names; — means no reviewed mapping. | position matched across quarters by exact reported CUSIP over a registry gap — never a name match | NEW / ADD / TRIM / EXIT by share count · NO CHANGE = same shares; the value moved with price, so never an ADD or a TRIM · EXIT = absent this quarter (disposed, delisted, confidential, or reported by an affiliate) — the filing does not say which · NO PRIOR = no comparable prior quarter on record (a first filing, or a quarter filed inside an affiliate's report), so not called a new stake · n/c = not classifiable: value undisclosed on one side of the pair, or neither shares nor value can classify it · †v: the reported share count is unchanged across the pair; this build's data classified the change from its reported value; builds from 2026-09-10 on read it as NO CHANGE | derived by Public Filings from the published data; “no value” means the source did not disclose a usable value — never zero | Prev value | Curr value | Prev shares | Curr shares | |
|---|---|---|---|---|---|---|---|---|
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12598 · issuer key iss:1082 | TRIM | +$9.7M | −100,000 | $256M | $265M | 3,286,830 | 3,186,830 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:11747 · issuer key iss:680 | ADD | +$149M | +2,486,997 | $32.6M | $182M | 8,757,249 | 11,244,246 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:11808 · issuer key iss:635 | TRIM | +$27.1M | −99,727 | $112M | $140M | 4,529,990 | 4,430,263 |
| — | share class as filed: SPONSORED ADS · position key pos:14374 · issuer key iss:248 | TRIM | −$13.8M | −35,000 | $152M | $138M | 500,000 | 465,000 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:11535 · issuer key iss:1757 | TRIM | +$46.0M | −2,508,269 | $72.3M | $118M | 8,165,374 | 5,657,105 |
| — | share class as filed: COM · position key sid:sec:prov:b23dd6a0ecec2737a5c87e9c74cf430d · issuer key cusip6:055477 | ADD | +$27.6M | +586,001 | $87.8M | $115M | 5,216,969 | 5,802,970 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:14656 · issuer key iss:1552 | TRIM | +$1.7M | −224,095 | $106M | $108M | 1,335,075 | 1,110,980 |
| — | share class as filed: COM · position key pos:15725 · issuer key iss:172 | ADD | +$1.7M | +115,000 | $99.6M | $101M | 1,500,476 | 1,615,476 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COMMON STOCK · position key pos:14234 · issuer key iss:1897 | NEW | +$95.1M | +1,505,374 | $0 | $95.1M | — | 1,505,374 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12517 · issuer key iss:1997 | ADD | +$40.2M | +505,803 | $36.4M | $76.7M | 812,761 | 1,318,564 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:13935 · issuer key iss:1355 | ADD | −$11.6M | +1,456,249 | $82.5M | $70.9M | 3,300,700 | 4,756,949 |
| — | share class as filed: COM · position key pos:14981 · issuer key iss:535 | ADD | −$1.0M | +396,000 | $70.2M | $69.1M | 1,507,636 | 1,903,636 |
| — | share class as filed: COM NEW · position key sid:sec:prov:3de8946eed46444b94fd5342eaddeac0 · issuer key cusip6:528872 | ADD | +$24.4M | +5,384,615 | $44.8M | $69.1M | 38,918,903 | 44,303,518 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:17421 · issuer key iss:475 | ADD | +$7.9M | +80,000 | $57.9M | $65.8M | 1,629,279 | 1,709,279 |
| — | share class as filed: COM · position key sid:sec:prov:3fee4169345e05a49cf14bcc2babfc71 · issuer key cusip6:86150R | TRIM | −$6.4M | −252,000 | $71.3M | $65.0M | 2,247,347 | 1,995,347 |
| — | share class as filed: SPONSORED ADS · position key sid:sec:prov:862b191ccb923fc424f39385b48ce4f8 · issuer key cusip6:86366E | ADD | −$11.0M | +250,000 | $75.0M | $64.0M | 1,078,698 | 1,328,698 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:16702 · issuer key iss:1556 | ADD | +$9.6M | +225,536 | $53.5M | $63.1M | 499,975 | 725,511 |
| — | share class as filed: SPONSORED ADS · position key pos:17964 · issuer key iss:2365 | TRIM | −$58.9M | −2,974,053 | $101M | $41.8M | 4,027,517 | 1,053,464 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM NEW · position key pos:12465 · issuer key iss:548 | NEW | +$40.5M | +613,952 | $0 | $40.5M | — | 613,952 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:13703 · issuer key iss:619 | TRIM | −$28.1M | −1,273,816 | $68.5M | $40.4M | 3,502,941 | 2,229,125 |
Flags: no row carries a flag.
1–20 of the 100 changes on this page
1–100 of 104 changes
Mark-to-market only (no share change) · 28
Positions whose share count is identical in both quarters; the value changed with price, not with a decision.
| The reviewed ticker for the filed issuer name and share class, the same mapping the Reported positions table uses. Symbols are never inferred from names; — means no reviewed mapping. | position matched across quarters by exact reported CUSIP over a registry gap — never a name match | NEW / ADD / TRIM / EXIT by share count · NO CHANGE = same shares; the value moved with price, so never an ADD or a TRIM · EXIT = absent this quarter (disposed, delisted, confidential, or reported by an affiliate) — the filing does not say which · NO PRIOR = no comparable prior quarter on record (a first filing, or a quarter filed inside an affiliate's report), so not called a new stake · n/c = not classifiable: value undisclosed on one side of the pair, or neither shares nor value can classify it · †v: the reported share count is unchanged across the pair; this build's data classified the change from its reported value; builds from 2026-09-10 on read it as NO CHANGE | derived by Public Filings from the published data; “no value” means the source did not disclose a usable value — never zero | Prev value | Curr value | Prev shares | Curr shares | |
|---|---|---|---|---|---|---|---|---|
| — | share class as filed: COM · position key pos:17712 · issuer key iss:1630 | NO CHANGE | +$55.3M | 0 | $477M | $532M | 10,825,013 | 10,825,013 |
| — | share class as filed: COM · position key sid:sec:prov:3c51cfeec4a5be695bdb08ebfaa41e00 · issuer key cusip6:03969F | NO CHANGE | −$6.7M | 0 | $71.7M | $65.0M | 3,007,077 | 3,007,077 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12161 · issuer key iss:587 | NO CHANGE | −$15.3M | 0 | $78.5M | $63.2M | 988,401 | 988,401 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM NEW · position key pos:11739 · issuer key iss:1687 | NO CHANGE | +$12.0M | 0 | $43.4M | $55.4M | 7,690,405 | 7,690,405 |
| — | share class as filed: COM · position key sid:sec:prov:c07b19289bd1953ef889bf232426771d · issuer key cusip6:81734D | NO CHANGE | −$7.7M | 0 | $55.8M | $48.1M | 2,000,000 | 2,000,000 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM NEW · position key pos:13625 · issuer key iss:45 | NO CHANGE | +$14.5M | 0 | $26.8M | $41.3M | 818,598 | 818,598 |
| — | share class as filed: SPONSORED ADS · position key sid:sec:prov:097fe4205cdb81b5acf642533490216f · issuer key cusip6:23306J | NO CHANGE | +$3.2M | 0 | $35.6M | $38.8M | 1,857,362 | 1,857,362 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: ORD SHS · position key pos:10692 · issuer key iss:2279 | NO CHANGE | −$15.1M | 0 | $46.0M | $30.9M | 9,969,495 | 9,969,495 |
| — | share class as filed: COM · position key sid:sec:prov:8948595df4e56c28a2e8dffed59ee810 · issuer key cusip6:24823R | NO CHANGE | +$3.8M | 0 | $23.1M | $26.8M | 1,396,513 | 1,396,513 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: SHS · position key pos:14281 · issuer key iss:2313 | NO CHANGE | −$23.9M | 0 | $41.7M | $17.8M | 2,450,000 | 2,450,000 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:12625 · issuer key iss:544 | NO CHANGE | +$4.6M | 0 | $12.4M | $17.0M | 1,193,410 | 1,193,410 |
| — | share class as filed: ADS · position key sid:sec:prov:5c7f5b7b9166fb5eb65582ad9f6aefb9 · issuer key cusip6:82686Q | NO CHANGE | −$2.4M | 0 | $17.7M | $15.3M | 2,911,438 | 2,911,438 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:10212 · issuer key iss:1665 | NO CHANGE | −$315K | 0 | $12.3M | $12.0M | 300,000 | 300,000 |
| — | share class as filed: COM NEW · position key sid:sec:prov:8cb65945c1d745d32abfa3ce25a4d2e9 · issuer key cusip6:45719W | NO CHANGE | −$2.2M | 0 | $12.0M | $9.8M | 5,850,000 | 5,850,000 |
| — | share class as filed: COM · position key sid:sec:prov:25db868bd92949401541405f5298734d · issuer key cusip6:56565P | NO CHANGE | +$1.2M | 0 | $7.9M | $9.1M | 450,000 | 450,000 |
| — | share class as filed: SPONSORED ADS · position key sid:sec:prov:35327bac9fdc9ba8e57fb291c13e050b · issuer key cusip6:44975P | NO CHANGE | −$4.6M | 0 | $11.9M | $7.4M | 3,000,000 | 3,000,000 |
| — | share class as filed: COM · position key pos:10682 · issuer key iss:2314 | NO CHANGE | +$2.1M | 0 | $5.0M | $7.2M | 2,082,000 | 2,082,000 |
| — | share class as filed: COM NEW · position key sid:sec:prov:9e958f4e10d0d474cc9e75d42ea33a9a · issuer key cusip6:88032L | NO CHANGE | +$1.6M | 0 | $5.2M | $6.8M | 427,141 | 427,141 |
| — | share class as filed: CL A NEW · position key sid:sec:prov:d870181e4209250aa4f0822ee5192029 · issuer key cusip6:918385 | NO CHANGE | −$53.8K | 0 | $6.5M | $6.5M | 163,000 | 163,000 |
| — | share class as filed: COM · position key sid:sec:prov:de0907d604dc0fc94b1a3f8dd009ab9f · issuer key cusip6:00534A | NO CHANGE | −$4.7M | 0 | $9.9M | $5.2M | 4,000,000 | 4,000,000 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: COM · position key pos:10533 · issuer key iss:1004 | NO CHANGE | −$2.7M | 0 | $7.6M | $4.9M | 170,000 | 170,000 |
| — | share class as filed: COM · position key sid:sec:prov:32df3091b0447927d2680841e51efc1f · issuer key cusip6:500946 | NO CHANGE | +$1.2M | 0 | $2.8M | $3.9M | 347,718 | 347,718 |
| — | share class as filed: COM NEW · position key sid:sec:prov:94240aadfa3d78ad689ccae76767f0be · issuer key cusip6:00847G | NO CHANGE | +$213K | 0 | $3.3M | $3.6M | 1,064,250 | 1,064,250 |
| — | share class as filed: COM · position key sid:sec:prov:d7ce1f7304a65bd9fa8becb1437c7f71 · issuer key cusip6:344174 | NO CHANGE | −$447K | 0 | $3.9M | $3.4M | 720,720 | 720,720 |
| — | share class as filed: COM · position key pos:11729 · issuer key iss:2412 | NO CHANGE | −$1.2M | 0 | $3.7M | $2.5M | 435,798 | 435,798 |
| — | share class as filed: COM · position key sid:sec:prov:cc23b1894e5c241f95346c4deeb13983 · issuer key cusip6:38341P | NO CHANGE | −$14.4M | 0 | $16.1M | $1.7M | 5,208,968 | 5,208,968 |
| a reviewed mapping row for this filed issuer name and share class (never inferred from the name) | share class as filed: ORDINARY SHARES · position key pos:17880 · issuer key iss:2302 | NO CHANGE | −$150K | 0 | $1.6M | $1.5M | 43,100 | 43,100 |
| — | share class as filed: COM CL A · position key sid:sec:prov:1266daf28de201038d46cc25c3965279 · issuer key cusip6:753018 | NO CHANGE | −$1.2M | 0 | $2.7M | $1.5M | 2,000,000 | 2,000,000 |
Flags: no row carries a flag.
Holdings without a security ID are counted, not compared. Method ↗
Reported positions — 2026-03-31
100 issuers · 102 rowsViewThis build carries one quarter for this manager: 2026-03-31. Notable managers carry four published quarters, others two.
| This list carries reported issuer names and security identities, without a dated ticker mapping. Symbols are not inferred from names. | a position composed from a base filing plus NEW-HOLDINGS amendments keeps every source row here; the composition's latest filed date is the one shown served from this build's published holdings (derived from the filer's own reported rows); every row resolves to its filing | Share of total reported value, calculated only when the full position list has disclosed values. This is 13F long value, not total assets. | value undisclosed on the filing: retained and counted, excluded from sums, never shown as $0 | Shares | Wt | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| — | Scholar Rock Holding Corp · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $532M | 10,825,013 | 14.8% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Kymera Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $265M | 3,186,830 | 7.4% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Erasca Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $182M | 11,244,246 | 5.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Edgewise Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $140M | 4,430,263 | 3.9% | |||||||
| — | BeOne Medicines AG · SPONSORED ADS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $138M | 465,000 | 3.8% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Tango Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $118M | 5,657,105 | 3.3% | |||||||
| — | Bicara Therapeutics Inc · COM CUSIP 055477103 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $115M | 5,802,970 | 3.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Revolution Medicines Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $108M | 1,110,980 | 3.0% | |||||||
| — | Arrowhead Pharmaceuticals Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $101M | 1,615,476 | 2.8% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Veradermics Inc · COMMON STOCK CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $95.1M | 1,505,374 | 2.6% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Xenon Pharmaceuticals Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $76.7M | 1,318,564 | 2.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Olema Pharmaceuticals Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $70.9M | 4,756,949 | 2.0% | |||||||
| — | Crinetics Pharmaceuticals Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $69.1M | 1,903,636 | 1.9% | |||||||
| — | Lexicon Pharmaceuticals Inc · COM NEW CUSIP 528872302 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $69.1M | 44,303,518 | 1.9% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Cogent Biosciences Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $65.8M | 1,709,279 | 1.8% | |||||||
| — | Stoke Therapeutics Inc · COM CUSIP 86150R107 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $65.0M | 1,995,347 | 1.8% | |||||||
| — | Arcus Biosciences Inc1 position · 2 reported rows
| $65.0M | 3,007,077 | 1.8% | |||||||
| — | Structure Therapeutics Inc · SPONSORED ADS CUSIP 86366E106 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $64.0M | 1,328,698 | 1.8% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Disc Medicine Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $63.2M | 988,401 | 1.8% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Rhythm Pharmaceuticals Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $63.1M | 725,511 | 1.7% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Solid Biosciences Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $55.4M | 7,690,405 | 1.5% | |||||||
| — | Septerna Inc · COM CUSIP 81734D104 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $48.1M | 2,000,000 | 1.3% | |||||||
| — | Centessa Pharmaceuticals PLC · SPONSORED ADS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $41.8M | 1,053,464 | 1.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Spyre Therapeutics Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $41.3M | 818,598 | 1.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Cytokinetics Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $40.5M | 613,952 | 1.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Dyne Therapeutics, Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $40.4M | 2,229,125 | 1.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Taysha Gene Therapies Inc · COM SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $39.5M | 8,829,913 | 1.1% | |||||||
| — | Dbv Technologies SA · SPONSORED ADS CUSIP 23306J309 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $38.8M | 1,857,362 | 1.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Oric Pharmaceuticals Inc | $38.0M | 2,998,192 | 1.1% | |||||||
| — | enGene Holdings Inc · COM CUSIP 29286M105 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $35.8M | 5,253,159 | 1.0% | |||||||
| — | Palvella Therapeutics Inc · COM CUSIP 697947109 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $32.1M | 257,485 | 0.9% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Taboola.com Ltd · ORD SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $30.9M | 9,969,495 | 0.9% | |||||||
| — | Enliven Therapeutics Inc · COM CUSIP 29337E102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $29.3M | 746,226 | 0.8% | |||||||
| — | Denali Therapeutics Inc · COM CUSIP 24823R105 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $26.8M | 1,396,513 | 0.7% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Remitly Global Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $24.2M | 1,543,271 | 0.7% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Damora Therapeutics Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $23.3M | 900,000 | 0.6% | |||||||
| — | Zura Bio Ltd · CLASS A ORD SHS CUSIP G9TY5A101 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $22.2M | 3,734,866 | 0.6% | |||||||
| — | Annexon Inc · COM CUSIP 03589W102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $21.9M | 3,958,646 | 0.6% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Trevi Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $21.3M | 1,786,867 | 0.6% | |||||||
| — | Rapport Therapeutics Inc · COM CUSIP 75383L102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $20.1M | 641,469 | 0.6% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Alphabet Inc · CAP STK CL A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $18.9M | 65,703 | 0.5% | |||||||
| — | Fulcrum Therapeutics Inc · COM CUSIP 359616109 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $18.0M | 2,350,000 | 0.5% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | WAVE Life Sciences Ltd · SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $17.8M | 2,450,000 | 0.5% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Definium Therapeutics Inc · COM SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $17.4M | 919,493 | 0.5% | |||||||
| — | Amylyx Pharmaceuticals Inc · COM CUSIP 03237H101 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $17.1M | 1,230,000 | 0.5% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Cullinan Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $17.0M | 1,193,410 | 0.5% | |||||||
| — | Neumora Therapeutics Inc · COM CUSIP 640979100 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $16.6M | 8,497,822 | 0.5% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Uniqure NV · SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $16.4M | 1,000,000 | 0.5% | |||||||
| — | CytomX Therapeutics Inc · COM CUSIP 23284F105 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $16.3M | 3,457,711 | 0.5% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | NVIDIA Corp · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $15.5M | 89,085 | 0.4% | |||||||
| — | Silence Therapeutics PLC · ADS CUSIP 82686Q101 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $15.3M | 2,911,438 | 0.4% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Microsoft Corp · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $15.3M | 41,380 | 0.4% | |||||||
| — | Monopar Therapeutics Inc · COM NEW CUSIP 61023L207 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $14.8M | 270,118 | 0.4% | |||||||
| — | Taiwan Semiconductor Manufacturing Co Ltd · SPONSORED ADS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $14.3M | 42,200 | 0.4% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Sionna Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $12.0M | 300,000 | 0.3% | |||||||
| — | Nebius Group NV · SHS CLASS A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $11.8M | 113,614 | 0.3% | |||||||
| — | Rezolute Inc · COM NEW CUSIP 76200L309 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $10.2M | 3,328,287 | 0.3% | |||||||
| — | Inhibikase Therapeutics Inc · COM NEW CUSIP 45719W205 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $9.8M | 5,850,000 | 0.3% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Amazon.com Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $9.7M | 46,641 | 0.3% | |||||||
| — | Generate Biomedicines Inc · COM SHS CUSIP 370920100 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $9.2M | 736,104 | 0.3% | |||||||
| — | MapLight Therapeutics Inc · COM CUSIP 56565P103 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $9.1M | 450,000 | 0.3% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | ServiceNow Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $9.1M | 87,090 | 0.3% | |||||||
| — | CrowdStrike Holdings Inc · CL A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $9.0M | 23,070 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | PDD Holdings Inc · SPONSORED ADS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $8.5M | 83,401 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Tesla Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $8.0M | 21,500 | 0.2% | |||||||
| — | NovaBridge Biosciences · SPONSORED ADS CUSIP 44975P103 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $7.4M | 3,000,000 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Bicycle Therapeutics PLC · SPONSORED ADS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $7.2M | 1,560,882 | 0.2% | |||||||
| — | Whitehawk Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $7.2M | 2,082,000 | 0.2% | |||||||
| — | Tenax Therapeutics Inc · COM NEW CUSIP 88032L605 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $6.8M | 427,141 | 0.2% | |||||||
| — | vTv Therapeutics Inc · CL A NEW CUSIP 918385204 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $6.5M | 163,000 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Datadog Inc · CL A COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $6.4M | 54,300 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Jfrog Ltd · ORD SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $6.0M | 128,816 | 0.2% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Dynatrace Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $5.5M | 150,000 | 0.2% | |||||||
| — | Workiva Inc · COM CL A CUSIP 98139A105 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $5.5M | 92,500 | 0.2% | |||||||
| — | Absci Corp · COM CUSIP 00091E109 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $5.4M | 1,800,000 | 0.1% | |||||||
| — | Invivyd Inc · COM CUSIP 00534A102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $5.2M | 4,000,000 | 0.1% | |||||||
| — | Satellos Bioscience Inc · COM CUSIP 80401L803 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $5.0M | 892,074 | 0.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | IONQ Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $4.9M | 170,000 | 0.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Broadcom Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $4.6M | 15,000 | 0.1% | |||||||
| — | Agomab Therapeutics NV · SPONSORED ADS CUSIP 00860C102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $4.3M | 411,250 | 0.1% | |||||||
| — | Cellebrite DI Ltd · ORDINARY SHARES CUSIP M2197Q107 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $4.3M | 311,544 | 0.1% | |||||||
| — | Seer Inc · COM CL A CUSIP 81578P106 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $4.1M | 2,458,673 | 0.1% | |||||||
| — | Korro Bio Inc · COM CUSIP 500946108 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $3.9M | 347,718 | 0.1% | |||||||
| — | Agenus Inc · COM NEW CUSIP 00847G804 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $3.6M | 1,064,250 | 0.1% | |||||||
| — | Foghorn Therapeutics Inc · COM CUSIP 344174107 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $3.4M | 720,720 | 0.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Forgent Power Solutions, Inc · COM SHS CL A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $2.9M | 100,000 | 0.1% | |||||||
| — | Kalaris Therapeutics Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $2.5M | 435,798 | 0.1% | |||||||
| — | GitLab Inc · CLASS A COM CUSIP 37637K108 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $2.2M | 100,000 | 0.1% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Micron Technology Inc · COM CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $2.0M | 6,000 | 0.1% | |||||||
| — | monday.com Ltd · SHS CUSIP M7S64H106 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $1.7M | 25,000 | 0.0% | |||||||
| — | Gossamer Bio Inc · COM CUSIP 38341P102 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $1.7M | 5,208,968 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Amer Sports Inc · COM SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $1.6M | 50,000 | 0.0% | |||||||
| — | KE Holdings Inc · SPONSORED ADS CUSIP 482497104 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $1.5M | 100,000 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | IREN Ltd · ORDINARY SHARES CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $1.5M | 43,100 | 0.0% | |||||||
| — | Rani Therapeutics Holdings Inc · COM CL A CUSIP 753018100 quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $1.5M | 2,000,000 | 0.0% | |||||||
| — | Aeva Technologies Inc · COM NEW CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d ticker not yet mapped | $1.4M | 110,000 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Medline Inc · COM CL A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $1.1M | 25,000 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Figma Inc · CLASS A COM STK CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $1.1M | 50,000 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Primo Brands Corp · CLASS A COM SHS CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $942K | 50,000 | 0.0% | |||||||
| verified against the SEC company list on 2026-09-10 — a reviewed mapping row for this filed issuer name and class (never inferred) | Nu Holdings Ltd. · ORD SHS CL A CUSIP — quarter ended 2026-03-31 filed filed 2026-05-14 +44d | $359K | 25,000 | 0.0% |
1–20 of 100 issuers
1–100 of 100 issuers · page 1 of 1
One line per issuer, largest first — open a line for its reported rows. Grouping ↗
Book shape
Tick = median of the 8,748 tracked filers with a 2026-03-31 book (the index median: the 8,662 with a complete book). Concentration uses reported 13F long value, not total assets; the index is withheld when any position lacks a value.- 74.7%below median 80.0%
- integer Herfindahl–Hirschman index in basis points over disclosed position values
- 429 bpsbelow median 446 bps
- holdings with no disclosed value (undisclosed, or unreadable on the filing) — kept and counted, never shown as zero
- 102 / 102median book 97.5 positions
132 quarter-over-quarter rows
Filing history
| Period | Source |
|---|---|
| 2026-03-31 | EDGAR ↗ |
Complete source filings on SEC EDGAR
The filing on EDGAR is the record, including any filed after this build.
Open Siren, L.L.C.'s 13F filings on SEC EDGAR ↗A 13F is a quarterly, long-only snapshot filed up to 45 days late — not current holdings. what a 13F covers ↗
13F reports cover LONG positions in Section 13(f) securities (US exchange-traded equities plus reportable options, warrants, certain convertibles) held by managers with at least $100M in such securities — so managers below that threshold are absent entirely. No short positions, no cash, no non-13(f) assets — not a full portfolio, and not a census of institutional ownership.
Positions are quarter-end snapshots filed up to 45 days late — not current holdings: a position may have changed or closed since the quarter ended.
Values are the manager's stated market value at quarter-end in era-dependent units (whole dollars for form versions effective 2023-01-03 onward, thousands before), normalized here to whole dollars; each record notes its original unit.
Affiliated managers may report the same position, so one position can appear under more than one filer.
Positions under confidential treatment may be omitted until a later amendment discloses them.
These are disclosures, not investment advice.