Bain Capital Life Sciences Investors, LLC
Sector Allocation
- Healthcare100.0%$1.7B
AUM History
13fpro.ai/research/fund/bain-capital-life-sciences-investors-llc-1703031
Conviction and streaks
Concentrating · top 10 = 87.9%From the fund's last 12 quarters of 13F filings: positions held longest at size, and names it added to or trimmed several quarters running.
Largest positions — Q2 2026
KLRA
$497.5MHTFL
$247.9MNAMS
$129.0MSVRA
$108.4MALKS
$101.5MSLDB
$98.0MPHVS
$92.5MOLMA
$88.6MCOAG
$60.6MCABA
$53.6MXFOR
$37.2MDNTH
$35.3MCCCC
$33.5MKYTX
$25.7MANNX
$25.3MRPID
$14.6MIRON
$10.3MAVIR
$9.7MXLO
$6.4MUPB
$4.2M
Top 20 stock positions. Options are left out: 13F reports them at the underlying's value.
13fpro.ai/research/fund/bain-capital-life-sciences-investors-llc-1703031
Bain Capital Life Sciences Investors, LLC 13F holdings — Q2 2026
$1.7B portfolio (+51.7% QoQ) · 21 holdings · Q2 2026 13F · top 10 are 88% of the stock portfolio
$497.5M
29.6% of stocks
NewThis quarter-26.8%Since filedNew this quarterHeld$247.9M
14.7% of stocks
-19%This quarter+37.4%Since filed4 qtrsHeldAIQuality35.3#2,300Est. buyEstimated buy price is Pro: unlock with a free trialTrimmed 2 qtrs in a row$129.0M
7.7% of stocks
-48%This quarter-24.0%Since filed10+ qtrsHeld$108.4M
6.5% of stocks
No changeThis quarter-9.7%Since filed10+ qtrsHeld$101.5M
6.0% of stocks
+218%This quarter-9.7%Since filed2 qtrsHeld$98.0M
5.8% of stocks
No changeThis quarter-32.7%Since filed10+ qtrsHeld$92.5M
5.5% of stocks
No changeThis quarter-9.1%Since filed10+ qtrsHeld$88.6M
5.3% of stocks
-5%This quarter-33.8%Since filed7 qtrsHeldAIQualityAI quality score is Pro: unlock with a free trialEst. buyEstimated buy price is Pro: unlock with a free trialTrimmed 2 qtrs in a row$60.6M
3.6% of stocks
NewThis quarter-30.1%Since filedNew this quarterHeld$53.6M
3.2% of stocks
+78%This quarter-47.1%Since filed10+ qtrsHeld
All holdings — Bain Capital Life Sciences Investors, LLC (Q2 2026)
21 disclosed positions from the Form 13F-HR on SEC EDGAR, with quarter-over-quarter share changes. Largest by value first; the ten above are not repeated.
| # | Company | Held | Source | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 11 | X4 Pharmaceuticals, Inc | Healthcare | $37.2M | 2.2% | 7.97M | — | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 12 | Dianthus Therapeutics, Inc. /DE/ | Healthcare | $35.3M | 2.1% | 362K | — | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 13 | C4 Therapeutics, Inc. | Healthcare | $33.5M | 2.0% | 7.17M | — | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 14 | Kyverna Therapeutics, Inc. | Healthcare | $25.7M | 1.5% | 2.88M | -7% | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 15 | Annexon, Inc. | Healthcare | $25.3M | 1.5% | 4.44M | -15% | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 16 | RAPID MICRO BIOSYSTEMS, INC. | Healthcare | $14.6M | 0.9% | 8.43M | — | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 17 | Disc Medicine, Inc. | Healthcare | $10.3M | 0.6% | 141K | — | 2 qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 18 | Atea Pharmaceuticals, Inc. | Healthcare | $9.7M | 0.6% | 2.08M | -12% | 10+ qtrsTrimmed 2 qtrs in a row | AI quality score is Pro: unlock with a free trial | 13F | |
| 19 | Xilio Therapeutics, Inc. | Healthcare | $6.4M | 0.4% | 664K | — | 10+ qtrs | AI quality score is Pro: unlock with a free trial | 13F | |
| 20 | Upstream Bio, Inc. | Healthcare | $4.2M | 0.3% | 601K | -31% | 7 qtrsTrimmed 3 qtrs in a row | AI quality score is Pro: unlock with a free trial | 13F | |
| 21 | NewAmsterdam Pharma Co N.V.warrant | Healthcare | $2.1M | 0.1% | 100K | — | 10+ qtrs | — | 13F |
What changed in Q2 2026
Against the previous quarter's 13F: 2 new, 2 added to, 7 trimmed, 1 sold out. Share-count changes; largest moves by dollar size first.
New positions (2)
Added to (2)
Trimmed (7)
now $129.0M · held 10+ qtrs
now $247.9M · held 4 qtrs, 2 trims in a row
now $88.6M · held 7 qtrs, 2 trims in a row
now $25.3M · held 10+ qtrs
now $25.7M · held 10+ qtrs
now $4.2M · held 7 qtrs, 3 trims in a row
+1 more in the Excel export
Sold out (1)
$CNTACentessa Pharmaceuticals plcwas $25.2M
held 1 qtr
Holdings by quarter
Every 13F Bain Capital Life Sciences Investors, LLC has filed, 34 earlier quarters. Pick one to see what it held then.
Is it too late to follow Bain Capital Life Sciences Investors?
Q2 2026 13F filed with the SEC on Aug 14, 2026. Prices are closing prices as of Oct 27, 2026.
Average quality of Bain Capital Life Sciences Investors's top 20 holdings: 33/100 (our AI quality score, weighted by position size; 7 of the 20 are scored)
Top 10 since filing
-13.9%
Value-weighted move of the 10 largest stock positions
Turnover
16%
Last quarter; 44% over the last 4
Top 10 weight
88%
Share of the stock portfolio in its 10 largest positions
Held 4+ quarters
60%
Share of portfolio value in positions held a year or more
Highest-quality names it owns(among its 100 largest positions)
The 7 highest-scoring companies in this portfolio are a Pro feature.
How these are measured
- Moves since the quarter-end and since the filing date use our own daily closing prices, from the close on (or just before) each date to the latest close.
- Turnover is the lesser of shares bought or sold in a quarter, valued at the quarter-end prices in the 13F, divided by the average of the two quarters' stock portfolio values.
- Quarters held and add/trim streaks count back only through quarters whose filed holdings add up to the filing's own cover-page total (back to Q1 2024 for this fund). A change counts as an add or a trim when the split-adjusted share count moves by more than 1%.
- Estimate, not the fund's reported cost. For each quarter in the current holding period in which the fund's share count rose (split-adjusted), we take that quarter's average daily close and weight it by the shares added; sales do not change an average cost. Quarters where the stock's price history and the 13F's own implied price disagree by more than 2x are left out.
- Put and call option rows report the value of the underlying shares, not a position the fund paid for, so they are left out of all of the above.
Portfolio Overview
Bain Capital Life Sciences Investors, LLC disclosed 21 positions worth $1.7B in its Form 13F-HR for Q2 2026, led by $KLRA (Kailera Therapeutics, Inc.) at 29.6% of the equity portfolio, followed by $HTFL and $NAMS. During the quarter the fund opened 2 new positions and exited 1 — including a new stake in $KLRA and a full exit from $CNTA. The portfolio is most concentrated in Healthcare (100.0% of disclosed assets). All figures are sourced directly from Bain Capital Life Sciences Investors, LLC’s Form 13F-HR filing with the SEC under CIK 1703031.
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AI-Powered Hedge Fund Analysis: Bain Capital Life Sciences Investors, LLC
13F Pro is an AI hedge fund tracker and stock research platform. For Bain Capital Life Sciences Investors, LLC (SEC CIK: 1703031), the platform ingests every quarterly Form 13F filing and applies AI-powered analysis on top — 10 specialized AI analysts (value, growth, momentum, macro, activist, and more) debate the fund's top positions and publish AI-generated analysis with cited SEC sources.
Every holding in Bain Capital Life Sciences Investors, LLC's portfolio is scored on an AI quality ranking built from its SEC filings (ROIC, FCF margin, revenue growth, institutional flow, earnings quality, shareholder dilution, and more). Track accumulation and distribution quarter over quarter, identify conviction positions, and see AI stock analysis for each position — alongside 8,700+ other institutional filers and 2,800+ AI-ranked companies.