Institutional Manager · CIK 0001678378
Mass General Brigham, Inc
SOMERVILLE, MA · File #028-17485
Latest AUM
$809.8M
Positions
7
Top-10 Concentration
100.0%
Filings
5
Portfolio Value Over Time
2023-12
2024-03
2024-06
2024-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| NEW | ISHARES TR | 464288257 | +4,613,955 | +$652.8M | $0 |
| NEW | KARMAN HLDGS INC | KRMN | +1,562,054 | +$114.3M | $0 |
| EXITED | SAMSARA INC | 79589L106 | -448,753 | -$21.6M | $0 |
| NEW | MAZE THERAPEUTICS INC | MAZE | +239,994 | +$9.9M | $0 |
| EXITED | PLIANT THERAPEUTICS INC | 729139105 | -288,690 | -$3.2M | $0 |
| NEW | MEDLINE INC | MDLN | +26,294 | +$1.1M | $0 |
| NEW | RUBRIK INC | RBRK | +14,000 | +$1.1M | $0 |
| EXITED | FULCRUM THERAPEUTICS INC | 359616109 | -205,356 | -$733,121 | $0 |
| ADD | REVOLUTION MEDICINES INC | RVMDW | +5,900 | +$469,935 | +$11.6M |
| REDUCE | TANGO THERAPEUTICS INC | TNGX | 0 | $0 | +$410,863 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 20257 pos · $809.8M
- 13F HOLDINGS REPORTQ/E Sep 202450 pos · $43.6M
- 13F HOLDINGS REPORTQ/E Jun 202452 pos · $20.5M
- 13F HOLDINGS REPORTQ/E Mar 202465 pos · $57.1M
- 13F HOLDINGS REPORTQ/E Dec 202320 pos · $10.8M
Top 7 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | ISHARES TR | 464288257 | 4,613,955 | $652.8M | 80.62% |
| 2 | KARMAN HLDGS INC | KRMN | 1,562,054 | $114.3M | 14.11% |
| 3 | REVOLUTION MEDICINES INC | RVMDW | 344,091 | $27.4M | 3.38% |
| 4 | MAZE THERAPEUTICS INC | MAZE | 239,994 | $9.9M | 1.23% |
| 5 | TANGO THERAPEUTICS INC | TNGX | 354,192 | $3.1M | 0.39% |
| 6 | MEDLINE INC | MDLN | 26,294 | $1.1M | 0.14% |
| 7 | RUBRIK INC | RBRK | 14,000 | $1.1M | 0.13% |