Mass General Brigham, Inc
Mass General Brigham, Inc reported 6 US-listed holdings worth $361.1 million in its 13F for the quarter ended 30 June 2026, filed 7 August 2026. Its largest: iShares Trust (54.8%), Karman Holdings Inc. (21.6%) and Revolution Medicines, Inc. (17.8%). Against the quarter before, it opened 0 positions, added to 0, trimmed 2 and sold out of 0.
The 6 largest of its 6 positions, each sized by its share of the reported holdings, coloured by the change in shares against Q1 2026.
What the fund reported holding at each quarter's end; hover a bar for the number of positions
What its reported holdings returned
Held through each quarter, the holdings it reported returned +6.2% over the 2 quarters to 30 June 2026, against +9.5% for the S&P 500.
Not the fund's own return: each 13F's holdings are kept unchanged until the next one, so trades inside a quarter, dividends, cash and fees are left out. A rough guide to how its picks have done over time.
What it did on the quarter
Its positions against its 13F for the quarter to 31 March 2026; a change under 0.1% of a position counts as held
Trimmed 2
- iShares Trust ACWI-893,820 shares · -42%
- Medline Inc. MDLN-1,944 shares · -3%
What it holds
| Company | Shares | Value | Of its book | Change in shares |
|---|---|---|---|---|
| iShares Trust ACWI | 1.3M | $197.7 million | 54.76% | -893.8K |
| Karman Holdings Inc. KRMN | 1.6M | $78.0 million | 21.60% | no change |
| Revolution Medicines, Inc. RVMD | 344.1K | $64.4 million | 17.85% | no change |
| Tango Therapeutics Inc. TNGX | 354.2K | $11.1 million | 3.07% | no change |
| Maze Therapeatics MAZE | 240.0K | $7.2 million | 1.98% | no change |
| Medline Inc. MDLN | 68.4K | $2.7 million | 0.75% | -1.9K |