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Bain Capital Life Sciences Investors, LLC

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13F filer, CIK 1703031, Boston, MA

Bain Capital Life Sciences Investors, LLC reported $799,265,446 across 23 holdings for the quarter ended 2025-06-30, in a 13F-HR filed 2025-08-14. Its ten largest share positions make up 87.4% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0000950123-25-008312

Period
2025-06-30
Reported value
$799M
Holdings
23
Top 10 weight
87.4%
New
1
Sold out
2

Part of the filer group Bain Capital Life Sciences Investors, LLC

How groups are built

Largest buys vs the previous quarter

SecurityShares changeApprox. value
CDTXadded+1,797,600$87.6M
CABAadded+6,916,237$10.5M
UPBadded+144,216$1.58M
XFORnew+563,859$1.07M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
IRONreduced-400,000-$21.2M
X4 PHARMACEUTICALS INCexited-16,915,784-$4M
DNTHreduced-207,457-$3.86M
NAUTexited-1,072,421-$923K

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q2 2025

Share positions as resolved from 13F-HR 0000950123-25-008312, largest first. % of portfolio is the value over $799,265,446, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
NAMSNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 10,473,913 shares; 2024Q4: 10,719,110 shares; 2025Q1: 10,719,110 shares; 2025Q2: 10,719,110 shares 10,719,110$194M24.29%0Timeline
CDTXCIDARA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 703,080 shares; 2024Q4: 703,080 shares; 2025Q1: 703,080 shares; 2025Q2: 2,500,680 shares 2,500,680$122M15.24%+1,797,600Timeline
NUVLNUVALENT INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,697,267 shares; 2024Q4: 1,447,267 shares; 2025Q1: 1,447,267 shares; 2025Q2: 1,447,267 shares 1,447,267$110M13.82%0Timeline
PHVSPHARVARIS N VQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,303,381 shares; 2024Q4: 3,303,381 shares; 2025Q1: 3,303,381 shares; 2025Q2: 3,303,381 shares 3,303,381$58.1M7.27%0Timeline
DNTHDIANTHUS THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,013,423 shares; 2024Q4: 2,689,707 shares; 2025Q1: 2,689,707 shares; 2025Q2: 2,482,250 shares 2,482,250$46.2M5.79%-207,457Timeline
SVRASAVARA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 14,565,457 shares; 2024Q4: 14,565,457 shares; 2025Q1: 17,600,621 shares; 2025Q2: 17,600,621 shares 17,600,621$40.1M5.02%0Timeline
SLDBSOLID BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 4,034,582 shares; 2024Q4: 4,034,582 shares; 2025Q1: 7,911,669 shares; 2025Q2: 7,911,669 shares 7,911,669$38.5M4.82%0Timeline
IRONDISC MEDICINE INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,795,735 shares; 2024Q4: 983,500 shares; 2025Q1: 983,500 shares; 2025Q2: 583,500 shares 583,500$30.9M3.87%-400,000Timeline
OLMAOLEMA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 7,470,214 shares; 2025Q1: 6,843,954 shares; 2025Q2: 6,843,954 shares 6,843,954$29.2M3.65%0Timeline
RPIDRAPID MICRO BIOSYSTEMS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 8,434,560 shares; 2024Q4: 8,434,560 shares; 2025Q1: 8,434,560 shares; 2025Q2: 8,434,560 shares 8,434,560$29.1M3.64%0Timeline
UPBUPSTREAM BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 2,295,322 shares; 2025Q1: 2,295,322 shares; 2025Q2: 2,439,538 shares 2,439,538$26.8M3.35%+144,216Timeline
CABACABALETTA BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,760,888 shares; 2024Q4: 2,760,888 shares; 2025Q1: 2,760,888 shares; 2025Q2: 9,677,125 shares 9,677,125$14.7M1.84%+6,916,237Timeline
TNGXTANGO THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,712,008 shares; 2024Q4: 2,712,008 shares; 2025Q1: 2,712,008 shares; 2025Q2: 2,712,008 shares 2,712,008$13.9M1.74%0Timeline
ANNXANNEXON INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 8,449,748 shares; 2024Q4: 5,249,069 shares; 2025Q1: 5,249,069 shares; 2025Q2: 5,249,069 shares 5,249,069$12.6M1.58%0Timeline
KYTXKYVERNA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,368,370 shares; 2024Q4: 3,368,370 shares; 2025Q1: 3,368,370 shares; 2025Q2: 3,368,370 shares 3,368,370$10.3M1.29%0Timeline
AVIRATEA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,485,638 shares; 2024Q4: 2,485,638 shares; 2025Q1: 2,485,638 shares; 2025Q2: 2,485,638 shares 2,485,638$8.95M1.12%0Timeline
XLOXilio Therapeutics Inc.Quarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 4,566,817 shares; 2024Q4: 4,566,817 shares; 2025Q1: 4,566,817 shares; 2025Q2: 4,566,817 shares 4,566,817$3.1M0.39%0Timeline
IPSCCENTURY THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 5,410,361 shares; 2024Q4: 5,410,361 shares; 2025Q1: 5,410,361 shares; 2025Q2: 5,410,361 shares 5,410,361$3.02M0.38%0Timeline
Mersana Therapeutics IncMersana Therapeutics IncQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 8,663,673 shares; 2024Q4: 8,663,673 shares; 2025Q1: 8,663,673 shares; 2025Q2: 8,663,673 shares 8,663,673$2.56M0.32%0
CCCCC4 THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,111,910 shares; 2024Q4: 1,111,910 shares; 2025Q1: 1,111,910 shares; 2025Q2: 1,111,910 shares 1,111,910$1.59M0.2%0Timeline
IVVDINVIVYD INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,799,595 shares; 2024Q4: 1,799,595 shares; 2025Q1: 1,799,595 shares; 2025Q2: 1,799,595 shares 1,799,595$1.29M0.16%0Timeline
XFORX4 PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: 563,859 shares 563,859$1.07M0.13%newTimeline
NAMSWNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 100,000 shares; 2024Q4: 100,000 shares; 2025Q1: 100,000 shares; 2025Q2: 100,000 shares 100,000$800K0.1%0Timeline

Sold out in Q2 2025

Positions in the previous quarter's report that this quarter's report no longer lists.

SecurityShares beforeValue beforeType
X4 PHARMACEUTICALS INCX4 PHARMACEUTICALS INC16,915,784$4Mshares
NAUTNAUTILUS BIOTECHNOLOGY INC1,072,421$923Kshares

How Q2 2025 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0000950123-25-008312 base2025-08-14acceptance time not in the bulk data set