Bain Capital Life Sciences Investors, LLC
Long book
$1.11B
Q1 2026
Positions
20
Top-10 weight
87%
concentration
Last quarter
+12.4%
SPY +14.8%
Turnover
30%
of book per quarter
Strategy in plain words
auto-generated from filingsBain Capital Life Sciences Investors, LLC is a concentrated fundamental stock-picker, specialised in healthcare (100% of the long book), running a $1.11B US long book across 20 positions.
The portfolio is extremely concentrated — the top 10 positions are almost the whole book. The portfolio is actively managed, with meaningful quarterly turnover. Current anchor positions: HEARTFLOW INC, NEWAMSTERDAM PHARMA CO NV, OLEMA PHARMACEUTICALS INC, SAVARA INC, PHARVARIS NV.
Over the last 9 quarters its long book ran on average 0.9pp per quarter behind the S&P 500, beating the index in 2 of 9 quarters. We rate its filings highest-signal: new buys here are worth attention.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
-20.9%
Q2 2024
+5.5%
Q3 2024
-3.3%
Q4 2024
-21.9%
Q1 2025
+4.7%
Q2 2025
+49.0%
Q3 2025
+17.6%
Q4 2025
-10.8%
Q1 2026
+12.4%
Sector allocation
Healthcare 100%
Long book by quarter
What does Bain Capital own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| HTFL HEARTFLOW INC | Healthcare | 10.4M | $254.2M | 22.9% | -16.1% |
| NAMS NEWAMSTERDAM PHARMA CO NV | Healthcare | 7.3M | $233.9M | 21.1% | Held |
| OLMA OLEMA PHARMACEUTICALS INC | Healthcare | 7.5M | $111.4M | 10.0% | -12.2% |
| SVRA SAVARA INC | Healthcare | 17.6M | $96.1M | 8.7% | Held |
| PHVS PHARVARIS NV | Healthcare | 2.7M | $75.6M | 6.8% | -4.5% |
| SLDB SOLID BIOSCIENCES INC | Healthcare | 9.8M | $70.6M | 6.4% | +24.0% |
| XFOR X4 PHARMACEUTICALS INC | Healthcare | 8.0M | $32.9M | 3.0% | Held |
| DNTH DIANTHUS THERAPEUTICS INC | Healthcare | 362.5K | $30.4M | 2.7% | -51.3% |
| ANNX ANNEXON INC | Healthcare | 5.2M | $28.9M | 2.6% | -0.7% |
| KYTX KYVERNA THERAPEUTICS INC | Healthcare | 3.1M | $26.8M | 2.4% | Held |
| CABA CABALETTA BIO INC | Healthcare | 9.7M | $26.0M | 2.3% | Held |
| ALKS ALKERMES PLC | Healthcare | 610.0K | $21.6M | 1.9% | New |
| RPID RAPID MICRO BIOSYSTEMS INC-A | Healthcare | 8.4M | $19.1M | 1.7% | Held |
| CCCC C4 THERAPEUTICS INC | Healthcare | 7.2M | $18.9M | 1.7% | Held |
| AVIR ATEA PHARMACEUTICALS INC | Healthcare | 2.4M | $12.7M | 1.1% | -5.0% |
| IRON DISC MEDICINE INC | Healthcare | 141.2K | $9.0M | 0.8% | New |
| UPB UPSTREAM BIO INC | Healthcare | 867.2K | $7.8M | 0.7% | -34.8% |
| XLO XILIO THERAPEUTICS INC | Healthcare | 664.0K | $5.6M | 0.5% | New |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 15, 2026 | 20 | $1.11B | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 17, 2026 | 19 | $1.31B | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 14, 2025 | 21 | $1.51B | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Aug 14, 2025 | 23 | $799.3M | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 15, 2025 | 24 | $675.9M | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 14, 2025 | 26 | $850.1M | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 14, 2024 | 24 | $961.2M | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 12, 2024 | 25 | $910.8M | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 15, 2024 | 26 | $1.24B | canonical | SEC ↗ |