Mass General Brigham, Inc
CIK
1678378
Location
SOMERVILLE, MA
Portfolio Value
Small
$176,209,673
Diversification
Highly concentrated
Filing Date
Global Rank
#4,469
/ 8,603
▲ 400
· as of Mar 2026
Top Industry
Aerospace & Defense
71.0%
3Y Alpha vs SPY
+16.4%
Period ended 3 months ago
Filed May 5, 2026 · 2mo
16 quarters · since Jun 2021
Clone Performance
Jul 2023–Jul 2026 · vs SPYHypothetical growth of cloning every reported 13F position and rebalancing on each filing, indexed to the same start.
Cloned portfolio
+139.1%
SPY
+76.0%
Annualised alpha
+13.0%
Max drawdown
−53.0%
Estimate. 13F holdings are quarter-lagged and long-only, so the clone rebalances about 45 days after each period end — when the filing becomes public — and excludes options and short positions. Past performance does not predict future results.
Portfolio Concentration
5 positions · as of Mar 31, 2026 · Δ vs Dec 31, 2025Top Position
71.0%
−1.9 pts
Top 5
100.0%
+0.7 pts
Top 10
100.0%
0.0 pts
HHI
5,434
Highly concentrated−219
Portfolio Trend
16 quarters · across all stocks
Sector Breakdown
As of Mar 31, 2026| Sector | % Portfolio | Value |
|---|---|---|
| Industrials | 71.0% | $125,042,422 |
| Healthcare | 29.0% | $51,167,251 |
Last Quarter's Activity
Export CSVAdded To
Positions the filer increased
1 positions
| Ticker | Company | Δ Shares | Shares | Value | Open |
|---|---|---|---|---|---|
| MDLN | Medline Inc. | +44,063 | 70,357 | $3,130,886 | |
| No positions match the current search. | |||||
Trimmed
Positions the filer reducedNo qualifying positions this quarter.
New Positions
Positions the filer opened this quarterNo qualifying positions this quarter.
Sold Out
Positions the filer fully exited
1 positions
| Ticker | Company | Shares | Value | Open |
|---|---|---|---|---|
| RBRK | Rubrik, Inc. | 14,000 | $1,070,720 | |
| No positions match the current search. | ||||
5 positions ·
$176,209,673 total
· as of Mar 31, 2026
| Ticker | Company | Type | Shares | Value (USD) | % of Portfolio | History |
|---|---|---|---|---|---|---|
| KRMN |
Karman Holdings Inc.
Industrials
|
Held | 1,562,054 | $125,042,422 | 70.96% | |
| RVMD |
Revolution Medicines, Inc.
Healthcare
|
Held | 344,091 | $33,462,849 | 18.99% | |
| TNGX |
Tango Therapeutics, Inc.
Healthcare
|
Held | 354,192 | $7,409,696 | 4.21% | |
| MAZE |
Maze Therapeutics, Inc.
Healthcare
|
Held | 239,994 | $7,163,820 | 4.07% | |
| MDLN |
Medline Inc.
Healthcare
|
Added | 70,357 | $3,130,886 | 1.78% |