Siren, L.L.C. holds a diversified book of 115 stocks worth $4.9B as of Q2 2026 (disclosed Aug 13, 2026, a ~44-day 13F lag). This quarter they opened Parabilis Medicines Inc and trimmed Scholar Rock Holding Corp. Their largest long position is Scholar Rock Holding Corp at 11% of the equity book. They also disclosed $15.6M in call options (bullish), shown separately below and excluded from the equity book.
Top-heavy: diversified book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
95% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
Other tracked managers holding the same core names as Siren, L.L.C.
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| GEODE CAPITAL MANAGEMENT, LLC | 79 / 80 | $363.2B |
| MORGAN STANLEY | 75 / 80 | $216.2B |
| UBS Group AG | 75 / 80 | $56.8B |
| BARCLAYS PLC | 73 / 80 | $44.7B |
| BlackRock, Inc. | 72 / 80 | $1.0T |
| JPMORGAN CHASE & CO | 72 / 80 | $217.8B |
| BANK OF AMERICA CORP /DE/ | 72 / 80 | $124.9B |
| GOLDMAN SACHS GROUP INC | 72 / 80 | $106.5B |
Ranked by how many of Siren, L.L.C.'s top 80 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Scholar Rock Holding Corp COM | $526.6M | 9.58M | 10.7% | ▼−12% Reduced · −1.3M sh | |
| 2 | Kymera Therapeutics Inc COM | $336.7M | 2.94M | 6.8% | ▼−7.9% Reduced · −251K sh | |
| 3 | Erasca Inc COM | $208.8M | 11.40M | 4.2% | ▲+1.4% Added · +154K sh | |
| 4 | Veradermics Inc COMMON STOCK | $203.5M | 1.66M | 4.1% | ▲+10.0% Added · +150K sh | |
| 5 | Tango Therapeutics Inc COM | $193.2M | 6.18M | 3.9% | ▲+9.2% Added · +522K sh | |
| 6 | Revolution Medicines Inc COM | $168.6M | 900.0K | 3.4% | ▼−19% Reduced · −211K sh | |
| 7 | Bicara Therapeutics Inc COM | $166.4M | 5.60M | 3.4% | ▼−3.4% Reduced · −200K sh | |
| 8 | Arrowhead Pharmaceuticals Inc COM | $139.8M | 1.72M | 2.8% | ▲+6.2% Added · +100K sh | |
| 9 | BeOne Medicines AG SPONSORED ADS | $132.5M | 465.0K | 2.7% | —Held | |
| 10 | Edgewise Therapeutics Inc COM | $129.4M | 3.18M | 2.6% | ▼−28% Reduced · −1.2M sh | |
| 11 | Rhythm Pharmaceuticals Inc COM | $126.2M | 1.14M | 2.6% | ▲+57% Added · +411K sh | |
| 12 | Lexicon Pharmaceuticals Inc COM NEW | $106.3M | 44.30M | 2.2% | —Held | |
| 13 | Enliven Therapeutics Inc COM | $90.1M | 1.77M | 1.8% | ▲+138% Added · +1.0M sh | |
| 14 | Spyre Therapeutics Inc COM NEW | $86.0M | 968.6K | 1.7% | ▲+18% Added · +150K sh | |
| 15 | Parabilis Medicines Inc COM | $81.9M | 2.99M | 1.7% | ▲New New position | |
| 16 | Xenon Pharmaceuticals Inc COM | $79.6M | 1.32M | 1.6% | —Held | |
| 17 | Solid Biosciences Inc COM NEW | $76.8M | 7.69M | 1.6% | —Held | |
| 18 | Abivax SA SPONSORED ADS | $76.8M | 576.0K | 1.6% | ▲New New position | |
| 19 | Hemab Therapeutics Holdings Inc COM SHS | $76.6M | 2.09M | 1.6% | ▲New New position | |
| 20 | Arcus Biosciences Inc COM | $74.6M | 2.42M | 1.5% | ▼−20% Reduced · −587K sh | |
| 21 | Cogent Biosciences Inc COM | $72.0M | 1.86M | 1.5% | ▲+8.8% Added · +150K sh | |
| 22 | Relay Therapeutics Inc COM | $68.3M | 3.65M | 1.4% | ▲New New position | |
| 23 | Taysha Gene Therapies Inc COM SHS | $67.1M | 9.85M | 1.4% | ▲+12% Added · +1.0M sh | |
| 24 | Definium Therapeutics Inc COM SHS | $66.8M | 1.42M | 1.4% | ▲+54% Added · +500K sh | |
| 25 | Stoke Therapeutics Inc COM | $65.3M | 2.00M | 1.3% | —Held | |
| 26 | Disc Medicine Inc COM | $65.0M | 888.4K | 1.3% | ▼−10% Reduced · −100K sh | |
| 27 | Cytokinetics Inc COM NEW | $64.7M | 759.0K | 1.3% | ▲+24% Added · +145K sh | |
| 28 | Septerna Inc COM | $63.6M | 1.90M | 1.3% | ▼−5.0% Reduced · −100K sh | |
| 29 | Olema Pharmaceuticals Inc COM | $60.8M | 4.86M | 1.2% | ▲+2.1% Added · +100K sh | |
| 30 | Crinetics Pharmaceuticals Inc COM | $53.2M | 1.42M | 1.1% | ▼−25% Reduced · −483K sh | |
| 31 | Kailera Therapeutics Inc COMMON STOCK | $48.8M | 2.21M | 1.0% | ▲New New position | |
| 32 | Dyne Therapeutics, Inc COM | $47.3M | 2.13M | 1.0% | ▼−4.5% Reduced · −100K sh | |
| 33 | Structure Therapeutics Inc SPONSORED ADS | $46.9M | 873.0K | 1.0% | ▼−34% Reduced · −456K sh | |
| 34 | Taboola.com Ltd ORD SHS | $42.1M | 8.42M | 0.9% | ▼−16% Reduced · −1.5M sh | |
| 35 | Palvella Therapeutics Inc COM | $39.3M | 257.5K | 0.8% | —Held | |
| 36 | Silence Therapeutics PLC ADS | $36.4M | 3.31M | 0.7% | ▲+14% Added · +400K sh | |
| 37 | Denali Therapeutics Inc COM | $35.9M | 1.40M | 0.7% | —Held | |
| 38 | Remitly Global Inc COM | $34.6M | 1.54M | 0.7% | —Held | |
| 39 | Cullinan Therapeutics Inc COM | $34.5M | 1.89M | 0.7% | ▲+59% Added · +700K sh | |
| 40 | Capital One Finl Corp COM | $34.4M | 171.6K | 0.7% | ▲New New position | |
| 41 | Trevi Therapeutics Inc COM | $33.3M | 1.79M | 0.7% | —Held | |
| 42 | Oric Pharmaceuticals Inc COM | $32.5M | 3.00M | 0.7% | —Held | |
| 43 | Alphabet Inc CAP STK CL A | $32.2M | 90.0K | 0.7% | ▲+37% Added · +24K sh | |
| 44 | Dbv Technologies SA SPONSORED ADS | $30.5M | 1.86M | 0.6% | —Held | |
| 45 | Absci Corp COM | $28.7M | 2.47M | 0.6% | ▲+37% Added · +675K sh | |
| 46 | Sionna Therapeutics Inc COM | $26.9M | 610.5K | 0.5% | ▲+104% Added · +311K sh | |
| 47 | Rapport Therapeutics Inc COM | $26.7M | 641.5K | 0.5% | —Held | |
| 48 | Amylyx Pharmaceuticals Inc COM | $26.6M | 1.48M | 0.5% | ▲+20% Added · +251K sh | |
| 49 | Annexon Inc COM | $25.5M | 4.46M | 0.5% | ▲+13% Added · +500K sh | |
| 50 | Monopar Therapeutics Inc COM NEW | $25.0M | 270.1K | 0.5% | —Held |
The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/2005245/holdings"
Use Arkolith to show Siren, L.L.C.'s latest holdings, largest changes, and filing provenance.
Put / call positions from the 13F — totals include every disclosed option leg
| Type | Underlying | Notional value | Underlying shares |
|---|---|---|---|
| CALL · bullish | MICROSOFT CORPMSFT | $9.0M | 24K |
| CALL · bullish | APPLE INCAAPL | $6.7M | 23K |
13F filers disclose option positions at the market value of the underlying the contracts reference, not the premium paid. A put is a bearish bet (it gains if the stock falls); a call is bullish. “Underlying shares” is the share count the contracts control, not a share holding. These legs are excluded from the equity book, weighting, concentration and sector figures above.
As-of date vs the date the SEC received each filing
| Quarter | As of | Filed | Positions | Value | Form |
|---|---|---|---|---|---|
| Q2 2026 | Jun 30, 2026 | Aug 13, 2026 | 119 | $4.9B | 13F-HR |
| Q1 2026 | Mar 31, 2026 | May 14, 2026 | 102 | $3.6B | 13F-HR |
| Q4 2025 | Dec 31, 2025 | Feb 13, 2026 | 115 | $3.4B | 13F-HR |
| Q3 2025 | Sep 30, 2025 | Nov 13, 2025 | 117 | $2.6B | 13F-HR |
| Q2 2025 | Jun 30, 2025 | Aug 13, 2025 | 111 | $1.9B | 13F-HR |
| Q1 2025 | Mar 31, 2025 | May 23, 2025 | 117 | $1.8B | 13F-HR/A |
| Q4 2024 | Dec 31, 2024 | Feb 14, 2025 | 119 | $2.3B | 13F-HR |
| Q3 2024 | Sep 30, 2024 | Nov 13, 2024 | 112 | $2.0B | 13F-HR |
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.