Bain Capital Life Sciences Investors, LLC — 13F Holdings & Portfolio
CIK 1703031 · latest 13F-HR filed 2026-05-15
Bain Capital Life Sciences Investors, LLC manages $1.11B in 13F-reported U.S. long-equity assets across 20 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are HTFL (22.93%), NAMS (21.09%), OLMA (10.05%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 4 new positions, exited 3, added to 5, and trimmed 8.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$1.11B
Long-equity book
20
Distinct positions
2026-03-31
Filed 2026-05-15
+4 / −3 / ↑5 / ↓8
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- SOLID BIOSCIENCES INC$26.0M +58.3%
- C4 THERAPEUTICS INC$5.2M +37.7%
- CABALETTA BIO INC$4.8M +22.8%
- ATEA PHARMACEUTICALS INC$3.8M +43.1%
- ANNEXON INC$2.5M +9.6%
Top Trims
- HEARTFLOW INC-$108.7M -29.9%
- OLEMA PHARMACEUTICALS INC-$101.3M -47.6%
- UPSTREAM BIO INC-$28.3M -78.4%
- NEWAMSTERDAM PHARMA COMPANY-$22.4M -8.8%
- SAVARA INC-$10.0M -9.5%
New Positions
- CENTESSA PHARMACEUTICALS$25.2M
- ALKERMES PLC$21.6M
- DISC MEDICINE INC$9.0M
- XILIO THERAPEUTICS INC$5.6M
Exited Positions
- MERSANA THERAPEUTICS INC$10.0M
- TANGO THERAPEUTICS INC$5.8M
- XILIO THERAPEUTICS INC$4.7M
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | HEARTFLOW INC | HTFL | 42238D107 | $254.2M | 22.93% | 10,448,158 | SH |
| 2 | NEWAMSTERDAM PHARMA COMPANY | NAMS | N62509109 | $233.9M | 21.09% | 7,306,566 | SH |
| 3 | OLEMA PHARMACEUTICALS INC | OLMA | 68062P106 | $111.4M | 10.05% | 7,473,238 | SH |
| 4 | SAVARA INC | SVRA | 805111101 | $96.1M | 8.67% | 17,600,621 | SH |
| 5 | PHARVARIS N V | PHVS | N69605108 | $75.6M | 6.82% | 2,675,509 | SH |
| 6 | SOLID BIOSCIENCES INC | SLDB | 83422E204 | $70.6M | 6.37% | 9,808,819 | SH |
| 7 | X4 PHARMACEUTICALS INC | XFOR | 98420X202 | $32.9M | 2.97% | 7,967,454 | SH |
| 8 | DIANTHUS THERAPEUTICS INC | DNTH | 252828108 | $30.4M | 2.74% | 362,470 | SH |
| 9 | ANNEXON INC | ANNX | 03589W102 | $28.9M | 2.60% | 5,212,674 | SH |
| 10 | KYVERNA THERAPEUTICS INC | KYTX | 501976104 | $26.8M | 2.42% | 3,110,000 | SH |
| 11 | CABALETTA BIO INC | CABA | 12674W109 | $26.0M | 2.35% | 9,677,125 | SH |
| 12 | CENTESSA PHARMACEUTICALS | CNTA | 152309100 | $25.2M | 2.27% | 635,000 | SH |
| 13 | ALKERMES PLC | ALKS | G01767105 | $21.6M | 1.95% | 610,000 | SH |
| 14 | RAPID MICRO BIOSYSTEMS INC | RPID | 75340L104 | $19.1M | 1.73% | 8,434,560 | SH |
| 15 | C4 THERAPEUTICS INC | CCCC | 12529R107 | $18.9M | 1.70% | 7,171,910 | SH |
| 16 | ATEA PHARMACEUTICALS INC | AVIR | 04683R106 | $12.7M | 1.15% | 2,360,638 | SH |
| 17 | DISC MEDICINE INC | IRON | 254604101 | $9.0M | 0.81% | 141,234 | SH |
| 18 | UPSTREAM BIO INC | UPB | 91678A107 | $7.8M | 0.70% | 867,211 | SH |
| 19 | XILIO THERAPEUTICS INC | XLO | 98422T209 | $5.6M | 0.50% | 664,021 | SH |
| 20 | NEWAMSTERDAM PHARMA COMPANY | NAMSW | N62509117 | $2.0M | 0.18% | 99,999 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-15 | $1.11B | 20 | 0001193125-26-226961 |
| 2025-12-31 | 2026-02-17 | $1.31B | 19 | 0001193125-26-054833 |
| 2025-09-30 | 2025-11-14 | $1.51B | 21 | 0001193125-25-283094 |