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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 $1,108,816,309 across 20 holdings for the quarter ended 2026-03-31, in a 13F-HR filed 2026-05-15. Its ten largest share positions make up 86.66% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0001193125-26-226961

Period
2026-03-31
Reported value
$1.11B
Holdings
20
Top 10 weight
86.66%
New
4
Sold out
3

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

How groups are built

Largest buys vs the previous quarter

SecurityShares changeApprox. value
CNTAnew+635,000$25.2M
ALKSnew+610,000$21.6M
SLDBadded+1,897,150$13.7M
IRONnew+141,234$9.03M
XLOnew+664,021$5.58M

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
HTFLreduced-2,000,000-$48.7M
DNTHreduced-381,122-$32M
OLMAreduced-1,035,403-$15.4M
MERSANA THERAPEUTICS INCexited-346,545-$10M
TNGXexited-653,493-$5.79M

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, Q1 2026

Share positions as resolved from 13F-HR 0001193125-26-226961, largest first. % of portfolio is the value over $1,108,816,309, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
HTFLHEARTFLOW INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 12,448,158 shares; 2025Q4: 12,448,158 shares; 2026Q1: 10,448,158 shares 10,448,158$254M22.93%-2,000,000Timeline
NAMSNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 10,473,913 shares; 2024Q4: 10,719,110 shares; 2025Q1: 10,719,110 shares; 2025Q2: 10,719,110 shares; 2025Q3: 10,719,110 shares; 2025Q4: 7,306,566 shares; 2026Q1: 7,306,566 shares 7,306,566$234M21.09%0Timeline
OLMAOLEMA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 7,470,214 shares; 2025Q1: 6,843,954 shares; 2025Q2: 6,843,954 shares; 2025Q3: 6,843,954 shares; 2025Q4: 8,508,641 shares; 2026Q1: 7,473,238 shares 7,473,238$111M10.05%-1,035,403Timeline
SVRASAVARA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 14,565,457 shares; 2024Q4: 14,565,457 shares; 2025Q1: 17,600,621 shares; 2025Q2: 17,600,621 shares; 2025Q3: 17,600,621 shares; 2025Q4: 17,600,621 shares; 2026Q1: 17,600,621 shares 17,600,621$96.1M8.67%0Timeline
PHVSPHARVARIS N VQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 3,303,381 shares; 2024Q4: 3,303,381 shares; 2025Q1: 3,303,381 shares; 2025Q2: 3,303,381 shares; 2025Q3: 3,181,275 shares; 2025Q4: 2,802,081 shares; 2026Q1: 2,675,509 shares 2,675,509$75.6M6.82%-126,572Timeline
SLDBSOLID BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 4,034,582 shares; 2024Q4: 4,034,582 shares; 2025Q1: 7,911,669 shares; 2025Q2: 7,911,669 shares; 2025Q3: 7,911,669 shares; 2025Q4: 7,911,669 shares; 2026Q1: 9,808,819 shares 9,808,819$70.6M6.37%+1,897,150Timeline
XFORX4 PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: 563,859 shares; 2025Q3: 2,436,588 shares; 2025Q4: 7,967,454 shares; 2026Q1: 7,967,454 shares 7,967,454$32.9M2.97%0Timeline
DNTHDIANTHUS THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 3,013,423 shares; 2024Q4: 2,689,707 shares; 2025Q1: 2,689,707 shares; 2025Q2: 2,482,250 shares; 2025Q3: 1,315,892 shares; 2025Q4: 743,592 shares; 2026Q1: 362,470 shares 362,470$30.4M2.74%-381,122Timeline
ANNXANNEXON INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 8,449,748 shares; 2024Q4: 5,249,069 shares; 2025Q1: 5,249,069 shares; 2025Q2: 5,249,069 shares; 2025Q3: 5,249,069 shares; 2025Q4: 5,249,069 shares; 2026Q1: 5,212,674 shares 5,212,674$28.9M2.6%-36,395Timeline
KYTXKYVERNA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 3,368,370 shares; 2024Q4: 3,368,370 shares; 2025Q1: 3,368,370 shares; 2025Q2: 3,368,370 shares; 2025Q3: 3,368,370 shares; 2025Q4: 3,110,000 shares; 2026Q1: 3,110,000 shares 3,110,000$26.8M2.42%0Timeline
CABACABALETTA BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 2,760,888 shares; 2024Q4: 2,760,888 shares; 2025Q1: 2,760,888 shares; 2025Q2: 9,677,125 shares; 2025Q3: 9,677,125 shares; 2025Q4: 9,677,125 shares; 2026Q1: 9,677,125 shares 9,677,125$26M2.35%0Timeline
CNTACENTESSA PHARMACEUTICALS PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 635,000 shares 635,000$25.2M2.27%newTimeline
ALKSALKERMES PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 610,000 shares 610,000$21.6M1.95%newTimeline
RPIDRAPID MICRO BIOSYSTEMS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 8,434,560 shares; 2024Q4: 8,434,560 shares; 2025Q1: 8,434,560 shares; 2025Q2: 8,434,560 shares; 2025Q3: 8,434,560 shares; 2025Q4: 8,434,560 shares; 2026Q1: 8,434,560 shares 8,434,560$19.1M1.73%0Timeline
CCCCC4 THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 1,111,910 shares; 2024Q4: 1,111,910 shares; 2025Q1: 1,111,910 shares; 2025Q2: 1,111,910 shares; 2025Q3: 1,111,910 shares; 2025Q4: 7,171,910 shares; 2026Q1: 7,171,910 shares 7,171,910$18.9M1.7%0Timeline
AVIRATEA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 2,485,638 shares; 2024Q4: 2,485,638 shares; 2025Q1: 2,485,638 shares; 2025Q2: 2,485,638 shares; 2025Q3: 2,485,638 shares; 2025Q4: 2,485,638 shares; 2026Q1: 2,360,638 shares 2,360,638$12.7M1.15%-125,000Timeline
IRONDISC MEDICINE INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 1,795,735 shares; 2024Q4: 983,500 shares; 2025Q1: 983,500 shares; 2025Q2: 583,500 shares; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 141,234 shares 141,234$9.03M0.81%newTimeline
UPBUPSTREAM BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 2,295,322 shares; 2025Q1: 2,295,322 shares; 2025Q2: 2,439,538 shares; 2025Q3: 2,439,538 shares; 2025Q4: 1,329,544 shares; 2026Q1: 867,211 shares 867,211$7.8M0.7%-462,333Timeline
XLOXILIO THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 664,021 shares 664,021$5.58M0.5%newTimeline
NAMSWNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: 100,000 shares; 2024Q4: 100,000 shares; 2025Q1: 100,000 shares; 2025Q2: 100,000 shares; 2025Q3: 100,000 shares; 2025Q4: 99,999 shares; 2026Q1: 99,999 shares 99,999$2M0.18%0Timeline

Sold out in Q1 2026

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

SecurityShares beforeValue beforeType
MERSANA THERAPEUTICS INCMERSANA THERAPEUTICS INC346,545$10Mshares
TNGXTANGO THERAPEUTICS INC653,493$5.79Mshares
XLOXilio Therapeutics Inc.7,372,686$4.72Mshares

How Q1 2026 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 0001193125-26-226961 base2026-05-15acceptance time not in the bulk data set