Stocks/Funds/CIK 1678378

Mass General Brigham, Inc

concentrated
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1678378
Assets
$469M
+720.8% YoY
Holdings
6
Lifetime alpha vs market
+9.42% annual
Average hold time
1.1 yr
median 0.9 yr

Quarterly history

Cum return +70% vs S&P +29% · α +40% lifetimeAUM $469M · peak $810MFlow $-435M (-54%)2016-032017-092019-092021-062022-092023-122026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
+0.00%
trims when stocks drop
when a holding falls −10%+
Middle response
+15.71%
steady accumulation
Rally response
+1.61%
adds into rallies
when a holding rises +10%+

Top positions · 6

Ticker$ value% portYoYHold time
ACWIiShares MSCI ACWI ETF$293M62.4%2.3 yr
KRMNKarman Holdings Inc.$125M26.7%0.5 yr
RVMDRevolution Medicines, In$33M7.1%+201.7%1.8 yr
TNGXTango Therapeutics, Inc.$7M1.6%+163.5%1.3 yr
MAZEMaze Therapeutics, Inc.$7M1.5%0.5 yr
MDLNMedline Inc.$3M0.7%0.5 yr

Portfolio composition (YoY)

Industry mix
Asset Management62.4%$293M
Aerospace & Defense26.7%$125M
Biotechnology10.2%-24.7pp$48M
Medical - Instruments & Supplies0.7%$3M
Country
US100.0%+0.0pp
Top 5: 99.3% · Top 10: 100.0% · Top 25: 100.0%

Winners

TickerPrev $PnLYoY %
RVMD$11M+0.02B201.7%
TNGX$3M+0.00B163.5%

Losers

TickerPrev $PnLYoY %

Top buys this quarter · 1

MDLN Medline Inc.+$2M

Top sells this quarter · 2

ACWI iShares MSCI ACWI ETF$0M
RBRK Rubrik, Inc.exit$1M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$469M6+53.40%+8.37%+45.03%-0.43B
2025-12-31$810M7+85.96%+25.10%+60.86%+0.76B
2024-09-30$44M5+266.38%+36.04%+230.35%+0.02B
2024-06-30$21M4+186.96%+24.49%+162.47%-0.03B
2024-03-31$57M5+239.54%+29.62%+209.92%+0.02B
2023-12-31$28M2+313.58%+26.18%+287.40%+0.00B
2023-09-30$11M2+10.38%+21.57%-11.19%-0.10B
2023-06-30$110M7+49.04%+19.42%+29.61%-0.04B
2023-03-31$128M6-67.43%-7.82%-59.61%-0.10B
2022-12-31$140M5-41.79%+7.56%-49.35%+0.03B
2022-09-30$192M3+37.15%-4.93%+42.08%-0.10B
2022-06-30$214M3-75.23%-16.11%-59.12%+0.16B
2022-03-31$235M3-0.05B
2021-12-31$282M3-0.09B
2021-09-30$371M7-0.04B
2021-06-30$410M9-0.23B