Q2 2026 13F · SEC CIK 1678378
Mass General Brigham, Inc
Investment managerFiled 2026-08-07 for Q2 2026. Open the filing ↗ · All SEC filings ↗
- Reported 13F value
- $361.1M
- Reported positions
- 6
- Holdings vs S&P 500, 3 yrs
- —
- Average holding period
- 3 qtrs
Mass General Brigham, Inc is an investment manager that reported 6 positions worth $361.1M in its Q2 2026 13F, filed 2026-08-07. Its largest holdings were Ishares Tr (ACWI, 54.8%), Karman Hldgs Inc (KRMN, 21.6%), Revolution Medicines Inc (RVMD, 17.8%).
Mass General Brigham, Inc holdings all 6 positions.
Weights are shares of the filer's total reported 13F value, compared with Q1 2026. Share changes may reflect splits; weight changes also reflect price moves. A 13F shows long US-listed positions only, up to 135 days after the fact.
| Stock | % of 13F value | Share change | Reported value |
|---|---|---|---|
| ACWIIshares Tr | 54.8% | -41.5% | $197.7M |
| KRMNKarman Hldgs Inc | 21.6% | +0.0% | $78.0M |
| RVMDRevolution Medicines Inc | 17.8% | +0.0% | $64.4M |
| TNGXTango Therapeutics Inc | 3.1% | +0.0% | $11.1M |
| MAZEMaze Therapeutics Inc | 2.0% | +0.0% | $7.2M |
| MDLNMedline Inc | 0.7% | -2.8% | $2.7M |
What Mass General Brigham, Inc bought and sold in Q2 2026, against Q1 2026.
New positions
No new positions among the largest holdings.
Added to
No position grew by more than 5%.
Reduced
- ACWI Ishares Tr-41.5% shares
Sold out
Nothing sold out.
Share counts compared with the Q1 2026 13F; a split also changes share counts.
How the holdings did against the S&P 500.
- 1 year
- —
- 3 years
- —
- 5 years
- +5.0% /yr
- S&P 500 +8.9%
A portfolio of the filer's 20 largest 13F positions, weighted by value, bought the trading day after each 13F was filed and held until the next one was: what copying this filer could have earned. 13Fs show long US-listed positions only, so this is an estimate of the stock picks, not the fund's reported returns.
Reported 13F value by quarter.
| Quarter | 13F value | Positions |
|---|---|---|
| Q2 2026 | $361.1M | 6 |
| Q1 2026 | $468.9M | 6 |
| Q4 2025 | $809.8M | 7 |
| Q3 2024 | $43.6M | 5 |
| Q1 2024 | $57.1M | 5 |
| Q2 2023 | $109.9M | 7 |
| Q1 2023 | $128.3M | 6 |
| Q4 2022 | $140.5M | 5 |
| Q1 2022 | $235.1M | 5 |
| Q4 2021 | $282.0M | 7 |
| Q3 2021 | $370.6M | 7 |
| Q2 2021 | $409.9M | 9 |
Questions about Mass General Brigham, Inc's portfolio
What stocks does Mass General Brigham, Inc own?
Mass General Brigham, Inc's latest 13F, for Q2 2026 and filed Aug 7, 2026, lists 6 positions worth $361.1M. The largest are Ishares Tr (ACWI) at 54.8%, Karman Hldgs Inc (KRMN) at 21.6%, Revolution Medicines Inc (RVMD) at 17.8%, Tango Therapeutics Inc (TNGX) at 3.1% and Maze Therapeutics Inc (MAZE) at 2.0%.
What did Mass General Brigham, Inc buy last quarter?
Mass General Brigham, Inc opened no new positions and grew none by more than 5% among its largest holdings in Q2 2026.
What did Mass General Brigham, Inc sell last quarter?
In Q2 2026, Mass General Brigham, Inc Ishares Tr (ACWI) (-41.5% shares), compared with its Q1 2026 filing.
When is Mass General Brigham, Inc's next 13F filing due?
13F filings are due 45 days after each quarter ends. Mass General Brigham, Inc's filing for the quarter ending Sep 30, 2026 is due by Nov 14, 2026; this page updates the day after it is published.