Arkolith/Funds/Bain Capital Life Sciences Investors, LLC

Bain Capital Life Sciences Investors, LLC

CIK 1703031
Holdings as of Mar 31, 2026·disclosed May 15, 2026·~45-day 13F lag·13F-HR
Active Filer

Bain Capital Life Sciences Investors, LLC holds a concentrated book of 19 stocks worth $1.1B as of Q1 2026 (disclosed May 15, 2026, a ~45-day 13F lag). This quarter they opened CENTESSA PHARMACEUTICALS and trimmed HEARTFLOW INC. Their largest long position is HEARTFLOW INC at 23% of the equity book.

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Use Arkolith to show Bain Capital Life Sciences Investors, LLC's latest
holdings, largest changes, and filing provenance.
Opened
3
new positions
Added to
1
existing
Trimmed
8
reduced
Sold out
2
exited

Concentration

Top-heavy: concentrated book

Top 5 holdings
70%
Top 10 holdings
87%
Top 20 holdings
100%

Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.

Direct sector allocation

5% mapped to company sectors

ETF / fund or unclassified
95%
Health Care
5%

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.

Biggest moves: latest quarter

Estimated $ traded · quarter-end prices, no cost basis

Bought
  • CENTESSA PHARMACEUTICALS
    ▲New$25.2M
  • ALKERMES PLC
    ▲New$21.6M
  • SOLID BIOSCIENCES INC
    ▲+24%$13.7M
  • DISC MEDICINE INC
    ▲New$9.0M
Trimmed / exited
  • XILIO THERAPEUTICS INCXLO
    ▼−91%$56.4M
  • HEARTFLOW INC
    ▼−16%$48.7M
  • DIANTHUS THERAPEUTICS INC
    ▼−51%$32.0M
  • OLEMA PHARMACEUTICALS INC
    ▼−12%$15.4M
  • UPSTREAM BIO INCUPB
    ▼−35%$4.2M
  • PHARVARIS N V
    ▼−4.5%$3.6M

Holdings: largest first

Bars show each stock's share of the portfolio. Click a row for its position history.

20 positions
#SecurityValueShares% PortLast moveHistory
1Heartflow Inc
COM
$254.2M10.45M
22.9%
▼−16%
Reduced · −2.0M sh
2Newamsterdam Pharma Company
ORDINARY SHARES
$233.9M7.31M
21.1%
—Held
3Olema Pharmaceuticals Inc
COM
$111.4M7.47M
10.0%
▼−12%
Reduced · −1.0M sh
4Savara Inc
COM
$96.1M17.60M
8.7%
—Held
5Pharvaris N V
COM
$75.6M2.68M
6.8%
▼−4.5%
Reduced · −127K sh
6Solid Biosciences Inc
COM NEW
$70.6M9.81M
6.4%
▲+24%
Added · +1.9M sh
7X4 Pharmaceuticals Inc
COM NEW
$32.9M7.97M
3.0%
—Held
8Dianthus Therapeutics Inc
COM
$30.4M362.5K
2.7%
▼−51%
Reduced · −381K sh
9Annexon Inc
COM
$28.9M5.21M
2.6%
▼−0.7%
Reduced · −36K sh
10Kyverna Therapeutics Inc
COM
$26.8M3.11M
2.4%
—Held
11Cabaletta Bio Inc
COM
$26.0M9.68M
2.3%
—Held
12Centessa Pharmaceuticals
SPONSORED ADS
$25.2M635.0K
2.3%
▲New
New position
13Alkermes PLC
SHS
$21.6M610.0K
1.9%
▲New
New position
14Rapid Micro Biosystems Inc
CLASS A COM
$19.1M8.43M
1.7%
—Held
15C4 Therapeutics Inc
COM STK
$18.9M7.17M
1.7%
—Held
16Atea Pharmaceuticals Inc
COM
$12.7M2.36M
1.1%
▼−5.0%
Reduced · −125K sh
17Disc Medicine Inc
COM
$9.0M141.2K
0.8%
▲New
New position
18Upstream Bio Inc
COM
$7.8M867.2K
0.7%
▼−35%
Reduced · −462K sh
19Xilio Therapeutics Inc
COM
$5.6M664.0K
0.5%
▲New
New position
20Newamsterdam Pharma Company
*W EXP 99/99/999
$2.0M100.0K
0.2%
—Held
Showing all 20 positions

Filing history

As-of date vs the date the SEC received each filing

QuarterAs ofFiledPositionsValueForm
Q1 2026Mar 31, 2026May 15, 202620$1.1B13F-HR
Q4 2025Dec 31, 2025Feb 17, 202619$1.3B13F-HR
Q3 2025Sep 30, 2025Nov 14, 202521$1.5B13F-HR
Q2 2025Jun 30, 2025Aug 14, 202523$799.3M13F-HR
Q1 2025Mar 31, 2025May 15, 202524$675.9M13F-HR
Q4 2024Dec 31, 2024Feb 14, 202526$850.1M13F-HR
Q3 2024Sep 30, 2024Nov 14, 202424$961.2M13F-HR
Q2 2024Jun 30, 2024Aug 12, 202425$910.8M13F-HR
Q1 2024Mar 31, 2024May 15, 202426$1.2B13F-HR
Q4 2023Dec 31, 2023Feb 13, 202427$1.0B13F-HR
Q3 2023Sep 30, 2023Nov 14, 202331$894.2M13F-HR
Q2 2023Jun 30, 2023Aug 14, 202332$971.0M13F-HR
Q1 2023Mar 31, 2023May 15, 202334$800.1M13F-HR
Q4 2022Dec 31, 2022Feb 14, 202333$894.8M13F-HR
Q3 2022Sep 30, 2022Nov 14, 202233$837.8M13F-HR
Q2 2022Jun 30, 2022Aug 15, 202235$852.7M13F-HR
Q1 2022Mar 31, 2022May 16, 202234$1.0B13F-HR
Q4 2021Dec 31, 2021Feb 14, 202234$1.3B13F-HR
Q3 2021Sep 30, 2021Nov 15, 202133$1.6B13F-HR
Q2 2021Jun 30, 2021Aug 16, 202130$1.5B13F-HR
Q1 2021Mar 31, 2021May 17, 202131$1.8B13F-HR
Q4 2020Dec 31, 2020Feb 16, 202126$1.6B13F-HR
Q3 2020Sep 30, 2020Nov 16, 202022$1.1B13F-HR
Q2 2020Jun 30, 2020Aug 14, 202015$954.8M13F-HR

Data source

Holdings from SEC EDGAR 13F-HR filings, updated quarterly ~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. The performance line is a simulation of the disclosed long book, not an audited return.