Arkolith/Funds/Siren, L.L.C.

Siren, L.L.C.

CIK: 2005245Q1 2026
Active Filer
Portfolio Value
$3.6B
Positions
134
New Buys
19
32 sold
Changes
35 ↑ / 18 ↓

Top HoldingsQ1 2026

134 total positions
#SecurityValueShares% PortChangeΔ Shares
1Scholar Rock Holding Corp
COM
$532.2M10.83M14.8%
HELD
0
2Kymera Therapeutics Inc
COM
$265.4M3.19M7.4%
REDUCED
-100,000
3Erasca Inc
COM
$181.9M11.24M5.0%
ADDED
+2.49M
4Edgewise Therapeutics Inc
COM
$139.6M4.43M3.9%
REDUCED
-99,727
5BeOne Medicines AG
SPONSORED ADS
$138.1M465.0K3.8%
REDUCED
-35,000
6Tango Therapeutics Inc
COM
$118.3M5.66M3.3%
REDUCED
-2,508,269
7Bicara Therapeutics Inc
COM
$115.4M5.80M3.2%
ADDED
+586.0K
8Revolution Medicines Inc
COM
$108.0M1.11M3.0%
REDUCED
-224,095
9Arrowhead Pharmaceuticals Inc
COM
$101.3M1.62M2.8%
ADDED
+115.0K
10Veradermics Inc
COMMON STOCK
$95.1M1.51M2.6%
NEW
11Xenon Pharmaceuticals Inc
COM
$76.7M1.32M2.1%
ADDED
+505.8K
12Olema Pharmaceuticals Inc
COM
$70.9M4.76M2.0%
ADDED
+1.46M
13Crinetics Pharmaceuticals Inc
COM
$69.1M1.90M1.9%
ADDED
+396.0K
14Lexicon Pharmaceuticals Inc
COM NEW
$69.1M44.30M1.9%
ADDED
+5.38M
15Cogent Biosciences Inc
COM
$65.8M1.71M1.8%
ADDED
+80.0K
16Stoke Therapeutics Inc
COM
$65.0M2.00M1.8%
REDUCED
-252,000
17Structure Therapeutics Inc
SPONSORED ADS
$64.0M1.33M1.8%
ADDED
+250.0K
18Disc Medicine Inc
COM
$63.2M988.4K1.8%
HELD
0
19Rhythm Pharmaceuticals Inc
COM
$63.1M725.5K1.7%
ADDED
+225.5K
20Solid Biosciences Inc
COM NEW
$55.4M7.69M1.5%
HELD
0
21Septerna Inc
COM
$48.1M2.00M1.3%
HELD
0
22Centessa Pharmaceuticals PLC
SPONSORED ADS
$41.8M1.05M1.2%
REDUCED
-2,974,053
23Spyre Therapeutics Inc
COM NEW
$41.3M818.6K1.1%
HELD
0
24Cytokinetics Inc
COM NEW
$40.5M614.0K1.1%
NEW
25Dyne Therapeutics, Inc
COM
$40.4M2.23M1.1%
REDUCED
-1,273,816
Showing top 25 of 134 positions

Filing History

Q1 2026102 pos
$3.6B
Q4 2025115 pos
$3.4B

Data Source

Holdings data sourced from SEC EDGAR 13F-HR filings. Updated quarterly, approximately 45 days after quarter end. All data is public domain.

Last filed: May 14, 2026