SL
Siren, L.L.C.: 13F Stock Holdings & Portfolio (Q2 2026)
Siren, L.L.C.CIK: 0002005245
Diversified strategySector-focusedMomentum follower
Total reported value
$4.9B
Reporting period: 2026-06-30 · Number of holdings: 119
Siren, L.L.C. disclosed 119 holdings in its latest 13F filing for the period ending 2026-06-30, with total reported value of $4.9B and a quarterly turnover rate of 42.9%.
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Personality snowflake
- Concentration
- 12.71
- Portfolio Stability
- 42.94
- Momentum
- 100
- Sector conviction
- 100
- Diversification
- 100
- Sizing Uniformity
- 83.54
Siren, L.L.C.'s disclosed holdings carry a Herfindahl concentration index of 0.032 — mathematically equivalent to about 31 equally-sized positions, well below its 119 actual disclosed holdings. That gap points to a strategy built around a small core of high-conviction bets rather than broad diversification.
Position sizes vary widely across the portfolio (a coefficient of variation of 1.65), with a handful of outsized bets alongside many smaller positions.
No strong tilt toward either adding to existing winners or initiating outsized new positions was observed in the latest reported quarter.
Sector classification currently covers about 12% of this portfolio's disclosed value; the remainder includes holdings (e.g. unmapped tickers, options, or other security types) not yet covered by our sector mapping.
Source and citation information
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Recent moves
View source Form 13F filing on SEC.govTrim SRRK
-11.5% -$5.5M
New buy 698955101
New buy ABVX
New buy 423494103
Add MANE
+10.0% $108.4M
New buy RLAY
Holdings Map
New buyAddUnchangedTrim
Top 10 holdings by weight
Full holdings list this quarter
Showing top 116 holdings (of 119 total)
| # | Ticker | Issuer | Asset Subclass | Weight | Weight Change | Shares Change | 4Q Trend |
|---|---|---|---|---|---|---|---|
| 1 | SRRK | Scholar Rock Holding CORP | Stock-Other | 10.66% | -4.09% | -11.55% | |
| 2 | KYMR | Kymera Therapeutics Inc | Stock-Other | 6.81% | -0.55% | -7.88% | |
| 3 | ERAS | Erasca Inc | Stock-Other | 4.23% | -0.81% | +1.37% | |
| 4 | MANE | Veradermics Inc | Stock-Other | 4.12% | +1.48% | +9.96% | |
| 5 | TNGX | Tango Therapeutics Inc | Stock-Other | 3.91% | +0.63% | +9.23% | |
| 6 | RVMD | Revolution Medicines Inc | Stock-Healthcare | 3.41% | +0.41% | -18.99% | |
| 7 | BCAX | Bicara Therapeutics Inc | Stock-Other | 3.37% | +0.17% | -3.45% | |
| 8 | ARWR | Arrowhead Pharmaceuticals In | Stock-Healthcare | 2.83% | +0.02% | +6.19% | |
| 9 | ONC | Beone Medicines Ltd-adr | Stock-Other | 2.68% | -1.15% | — | |
| 10 | EWTX | Edgewise Therapeutics Inc | Stock-Other | 2.62% | -1.25% | -28.12% | |
| 11 | RYTM | Rhythm Pharmaceuticals Inc | Stock-Other | 2.55% | +0.80% | +56.62% | |
| 12 | LXRX | Lexicon Pharmaceuticals Inc | Stock-Other | 2.15% | +0.23% | — | |
| 13 | ELVN | Enliven Therapeutics Inc | Stock-Other | 1.82% | +1.01% | +137.78% | |
| 14 | SYRE | Spyre Therapeutics Inc | Stock-Other | 1.74% | +0.60% | +18.32% | |
| 15 | ✓ | Stock-Other | 1.66% | +1.66% | NEW | ||
| 16 | XENE | Xenon Pharmaceuticals Inc | Stock-Other | 1.61% | -0.52% | — | |
| 17 | SLDB | Solid Biosciences Inc | Stock-Other | 1.55% | +0.02% | — | |
| 18 | ABVX | Abivax Sa-adr | Stock-Other | 1.55% | +1.55% | NEW | |
| 19 | ✓ | Stock-Other | 1.55% | +1.55% | NEW | ||
| 20 | RCUS | Arcus Biosciences Inc | Stock-Other | 1.51% | -0.29% | -19.51% | |
| 21 | COGT | Cogent Biosciences Inc | Stock-Other | 1.46% | -0.36% | +8.78% | |
| 22 | RLAY | Relay Therapeutics Inc | Stock-Other | 1.38% | +1.38% | NEW | |
| 23 | TSHA | Taysha Gene Therapies Inc | Stock-Other | 1.36% | +0.27% | +11.51% | |
| 24 | DFTX | Definium Therapeutics Inc | Stock-Other | 1.35% | +0.87% | +54.38% | |
| 25 | STOK | Stoke Therapeutics Inc | Stock-Other | 1.32% | -0.48% | — | |
| 26 | IRON | Disc Medicine Inc | Stock-Other | 1.31% | -0.43% | -10.12% | |
| 27 | CYTK | Cytokinetics Inc | Stock-Healthcare | 1.31% | +0.19% | +23.62% | |
| 28 | SEPN | Septerna Inc | Stock-Other | 1.29% | -0.04% | -5.00% | |
| 29 | OLMA | Olema Pharmaceuticals Inc | Stock-Other | 1.23% | -0.74% | +2.10% | |
| 30 | CRNX | Crinetics Pharmaceuticals In | Stock-Other | 1.08% | -0.84% | -25.36% | |
| 31 | ✓ | Stock-Other | 0.99% | +0.99% | NEW | ||
| 32 | DYN | Dyne Therapeutics Inc | Stock-Other | 0.96% | -0.16% | -4.49% | |
| 33 | GPCR | Structure Therapeutics Inc | Stock-Other | 0.95% | -0.83% | -34.30% | |
| 34 | TBLA | Taboola.com Ltd. | Stock-Other | 0.85% | -0.01% | -15.51% | |
| 35 | PVLA | Palvella Therapeutics Inc | Stock-Other | 0.80% | -0.09% | — | |
| 36 | SLN | Silence Therapeutics Plc-adr | Stock-Other | 0.74% | +0.31% | +13.74% | |
| 37 | DNLI | Denali Therapeutics Inc | Stock-Other | 0.73% | -0.01% | — | |
| 38 | RELY | Remitly Global Inc | Stock-Other | 0.70% | +0.03% | — | |
| 39 | CGEM | Cullinan Therapeutics Inc | Stock-Other | 0.70% | +0.23% | +58.66% | |
| 40 | COF | Capital One Financial CORP | Stock-Financials | 0.70% | +0.70% | NEW | |
| 41 | TRVI | Trevi Therapeutics Inc | Stock-Other | 0.67% | +0.08% | — | |
| 42 | ORIC | Oric Pharmaceuticals Inc | Stock-Other | 0.66% | -0.39% | — | |
| 43 | GOOGL | Alphabet Inc-cl A | Stock-Comm Services | 0.65% | +0.13% | +36.98% | |
| 44 | DBVT | Dbv Technologies Sa-spon Adr | Stock-Other | 0.62% | -0.46% | — | |
| 45 | ABSI | Absci CORP | Stock-Other | 0.58% | +0.43% | +37.49% | |
| 46 | SION | Sionna Therapeutics Inc | Stock-Other | 0.54% | +0.21% | +103.50% | |
| 47 | RAPP | Rapport Therapeutics Inc | Stock-Other | 0.54% | -0.02% | — | |
| 48 | AMLX | Amylyx Pharmaceuticals Inc | Stock-Other | 0.54% | +0.07% | +20.37% | |
| 49 | ANNX | Annexon Inc | Stock-Other | 0.52% | -0.09% | +12.63% | |
| 50 | MNPR | Monopar Therapeutics Inc | Stock-Other | 0.51% | +0.10% | — |
1–50 of 116
Portfolio Performance
Performance for Q3 2026
+19.3%
Performance Last 4 Quarters
+94.1%
- Stdev
- +27.3%
- Beta
- +0.58
- Alpha
- +26.2%
- Max Drawdown
- -22.3%
- Annualized Perf
- +37.2%
- Batting Avg vs S&P
- +61.9%
- Sortino
- +2.71
- Stutzer
- +0.39
- Treynor
- +0.61
- Sterling
- +2.65
- Calmar
- +1.67
- Information Ratio
- +0.73
- Tracking Error
- +26.8%
- Stdev Down
- +13.1%
- Winning Months %
- +71.4%
- Losing Months %
- +28.6%
- Best 12 Months
- +113.3%
- Worst 12 Months
- +27.4%
- Efficiency Ratio
- +0.52
- Sharpe
- +1.3
- Stdev Sectors
- +22.1%
- Skewness
- +0.11
- Kurtosis
- -0.69
- Upside Potential
- +4.44
Reported value over time
Sector allocation
Sector allocation over time
Quarterly history
Holding changes this quarter
Siren, L.L.C.'s most significant position changes for 2026-06-30: New buy: ; New buy: Abivax Sa-adr (ABVX); New buy: ; New buy: Relay Therapeutics Inc (RLAY); New buy: .
| # | Ticker | Issuer | Weight Change | Shares Change | Action |
|---|---|---|---|---|---|
| 1 | ✓ | +1.7% | NEW | New buy | |
| 2 | ABVX | Abivax Sa-adr | +1.6% | NEW | New buy |
| 3 | ✓ | +1.6% | NEW | New buy | |
| 4 | MANE | Veradermics Inc | +1.5% | +9.96% | Add |
| 5 | RLAY | Relay Therapeutics Inc | +1.4% | NEW | New buy |
| 6 | ELVN | Enliven Therapeutics Inc | +1% | +137.78% | Add |
| 7 | ✓ | +1% | NEW | New buy | |
| 8 | DFTX | Definium Therapeutics Inc | +0.9% | +54.38% | Add |
| 9 | RYTM | Rhythm Pharmaceuticals Inc | +0.8% | +56.62% | Add |
| 10 | COF | Capital One Financial CORP | +0.7% | NEW | New buy |
| 11 | TNGX | Tango Therapeutics Inc | +0.6% | +9.23% | Add |
| 12 | SYRE | Spyre Therapeutics Inc | +0.6% | +18.32% | Add |
| 13 | ORKA | Oruka Therapeutics Inc | +0.5% | NEW | New buy |
| 14 | ✓ | +0.5% | NEW | New buy | |
| 15 | TYRA | Tyra Biosciences Inc | +0.5% | NEW | New buy |
| 16 | ABSI | Absci CORP | +0.4% | +37.49% | Add |
| 17 | RVMD | Revolution Medicines Inc | +0.4% | -18.99% | Trim |
| 18 | SLN | Silence Therapeutics Plc-adr | +0.3% | +13.74% | Add |
| 19 | TSHA | Taysha Gene Therapies Inc | +0.3% | +11.51% | Add |
| 20 | LXRX | Lexicon Pharmaceuticals Inc | +0.2% | — | Unchanged |
| 21 | CGEM | Cullinan Therapeutics Inc | +0.2% | +58.66% | Add |
| 22 | ADAG | Adagene Inc-adr | +0.2% | NEW | New buy |
| 23 | ENGN | Engene Therapeutics Inc | +0.2% | NEW | New buy |
| 24 | SION | Sionna Therapeutics Inc | +0.2% | +103.50% | Add |
| 25 | CYTK | Cytokinetics Inc | +0.2% | +23.62% | Add |
| 26 | OCS | Oculis Holding AG | +0.2% | NEW | New buy |
| 27 | BCAX | Bicara Therapeutics Inc | +0.2% | -3.45% | Trim |
| 28 | DSGN | Design Therapeutics Inc | +0.2% | NEW | New buy |
| 29 | GOOGL | Alphabet Inc-cl A | +0.1% | +36.98% | Add |
| 30 | AAPL | Apple Inc | +0.1% | NEW | New buy |
| 31 | IREN | IREN Limited | +0.1% | +306.03% | Add |
| 32 | ✓ | +0.1% | NEW | New buy | |
| 33 | MNPR | Monopar Therapeutics Inc | +0.1% | — | Unchanged |
| 34 | BABA | Alibaba Group Holding-sp Adr | +0.1% | NEW | New buy |
| 35 | OUST | Ouster Inc | +0.1% | NEW | New buy |
| 36 | TRVI | Trevi Therapeutics Inc | +0.1% | — | Unchanged |
| 37 | MPLT | Maplight Therapeutics Inc | +0.1% | — | Unchanged |
| 38 | PALI | Palisade Bio Inc | +0.1% | NEW | New buy |
| 39 | ✓ | +0.1% | NEW | New buy | |
| 40 | AMLX | Amylyx Pharmaceuticals Inc | +0.1% | +20.37% | Add |
| 41 | RZLT | Rezolute Inc | +0.1% | — | Unchanged |
| 42 | AVGO | Broadcom Inc | +0.1% | +66.67% | Add |
| 43 | ZTS | Zoetis Inc | +0.1% | NEW | New buy |
| 44 | MSFT | Microsoft CORP | 0% | +48.62% | Add |
| 45 | IONQ | Ionq Inc | 0% | — | Unchanged |
| 46 | AEVA | Aeva Technologies Inc | 0% | +32.24% | Add |
| 47 | NFLX | Netflix Inc | 0% | NEW | New buy |
| 48 | RELY | Remitly Global Inc | 0% | — | Unchanged |
| 49 | TSM | Taiwan Semiconductor-sp Adr | 0% | +5.92% | Add |
| 50 | DDOG | Datadog Inc - Class A | 0% | -26.34% | Trim |
1–50 of 126
Filing History
FAQ
What is Siren, L.L.C. and what type of investor is it?
Siren, L.L.C. is an investment manager that files SEC Form 13F quarterly, disclosing its U.S. public equity holdings to regulators. As of the most recent reporting period (2026-06-30), the firm manages a tracked equity portfolio valued at approximately $4.9B, spread across 119 disclosed positions.
What are Siren, L.L.C.'s largest equity positions?
Based on the latest 13F filing, Siren, L.L.C.'s top holdings by market value are:
1. Scholar Rock Holding CORP (SRRK) — $526.6M (10.7%)
2. Kymera Therapeutics Inc (KYMR) — $336.7M (6.8%)
3. Erasca Inc (ERAS) — $208.8M (4.2%)
4. Veradermics Inc (MANE) — $203.5M (4.1%)
5. Tango Therapeutics Inc (TNGX) — $193.2M (3.9%)
What changes did Siren, L.L.C. make in its most recent portfolio filing?
In the latest reported quarter, Siren, L.L.C. made 88 notable position adjustments: 26 new positions were initiated, 32 existing holdings were added to, 20 positions were partially reduced, and 10 were completely exited. The largest of these moves: New buy: ; New buy: Abivax Sa-adr (ABVX); New buy: ; New buy: Relay Therapeutics Inc (RLAY); New buy:
What sectors does Siren, L.L.C. focus on?
Siren, L.L.C. is concentrated in the following sectors based on its current disclosed equity portfolio:
• Health Care: 61.7%
• Information Technology: 23.3%
• Communication Services: 5.8%
• Financials: 5.7%
• Consumer Discretionary: 3.5%
Investment Profile
Siren, L.L.C. returned an annualized 37.2% over the trailing 21 months — outperforming the S&P 500 by 26.2 points — based on a reconstructed track record of its disclosed 13F positions, with a beta of 0.58 (less volatile than the market) and a 62% quarterly batting average against the index.
Its portfolio is broadly diversified and moderately active, with 61.7% of the portfolio concentrated in Health Care.
Its turnover score has risen from 0 to 43 over the past 4 quarters — a shift toward more active trading.
It has added to its ERAS position over the past two quarters (+$176.2M, now $208.8M), while trimming GPCR over the same stretch (-$28.2M, still holding $46.9M).
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Developer Access
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REST API
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