Stocks/Funds/CIK 1513211

Main Street Research LLC

long-term holder
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1513211
Assets
$1.72B
+12.3% YoY
Holdings
148
Lifetime alpha vs market
+6.51% annual
Average hold time
4.2 yr
median 2.9 yr

Quarterly history

Cum return +238% vs S&P +125% · α +114% lifetimeAUM $1.7B · peak $1.9BFlow $20M (+1%)2016-032017-092019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-20.22%
trims when stocks drop
when a holding falls −10%+
Middle response
-2.00%
baseline attrition
Rally response
-2.78%
trims into rallies
when a holding rises +10%+

Top positions · 30

Ticker$ value% portYoYHold time
NVDANVIDIA Corporation$108M6.3%+60.9%5.5 yr
AAPLApple Inc.$102M6.0%+14.7%10.3 yr
GOOGLAlphabet Inc.$90M5.2%6.3 yr
ISCFiShares International Sm$82M4.8%0.8 yr
TSMTaiwan Semiconductor Man$75M4.4%+105.6%4.0 yr
XBIState Street SPDR S&P Bi$72M4.2%0.5 yr
JPMJPMorgan Chase & Co.$66M3.8%+21.8%4.8 yr
AVGOBroadcom Inc.$66M3.8%+86.0%6.3 yr
MCKMcKesson Corporation$59M3.4%+29.1%4.3 yr
AMZNAmazon.com, Inc.$56M3.3%+9.5%10.3 yr
ASMLASML Holding N.V.$55M3.2%+100.9%7.3 yr
GLWCorning Incorporated$53M3.1%+201.5%0.3 yr
COSTCostco Wholesale Corpora$46M2.7%+5.9%10.3 yr
JNJJohnson & Johnson$46M2.7%+51.5%10.3 yr
EWYiShares MSCI South Korea$45M2.6%0.5 yr

Portfolio composition (YoY)

Industry mix
Semiconductors20.1%+12.1pp$346M
Asset Management15.5%+14.1pp$266M
Internet Content & Information8.0%+1.0pp$137M
Banks - Diversified7.3%+3.7pp$126M
Hardware, Equipment & Parts7.2%+7.1pp$123M
Consumer Electronics6.0%+0.5pp$102M
Drug Manufacturers - General5.2%+4.7pp$90M
Discount Stores5.2%+1.3pp$89M
Medical - Distribution3.4%+0.4pp$59M
Specialty Retail3.3%-2.5pp$56M
Country
US82.2%-5.5pp
CA4.6%
TW4.4%+2.5pp
GB3.3%+1.1pp
NL3.2%+3.2pp
AU2.2%
IE0.1%-0.9pp
JP0.0%
Top 5: 26.6% · Top 10: 45.2% · Top 25: 83.1%

Winners

TickerPrev $PnLYoY %
PLTR$76M+0.06B73.3%
AVGO$45M+0.04B86.0%
CAT$33M+0.04B117.8%
TSM$29M+0.03B105.6%
NVDA$49M+0.03B60.9%

Losers

TickerPrev $PnLYoY %
PG$68M-0.01B-12.9%
MSFT$50M-0.00B-0.6%
META$59M-0.00B-0.4%

Top buys this quarter · 15

GLW Corning Incorporatednew+$53M
AZN AstraZeneca PLCnew+$38M
RY Royal Bank of Canadanew+$36M
MU Micron Technology, Inc.+$35M
KEYS Keysight Technologies, Inc.new+$32M
AAPL Apple Inc.+$29M
BHP BHP Group Limited+$15M
FICO Fair Isaac Corporation+$6M
NVDA NVIDIA Corporation+$108M
PANW Palo Alto Networks, Inc.+$3M

Top sells this quarter · 15

V Visa Inc.$50M
PLTR Palantir Technologies Inc.$40M
MSFT Microsoft Corporation$37M
HOOD Robinhood Markets, Inc.$37M
UBER Uber Technologies, Inc.$31M
DHI D.R. Horton, Inc.$29M
COP ConocoPhillips$29M
IBN ICICI Bank Limitedexit$26M
GS The Goldman Sachs Group, Inc.$21M
BCS Barclays PLC$18M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$1.72B148+24.18%+17.59%+6.59%+0.02B
2025-12-31$1.75B129+23.56%+17.72%+5.84%-0.11B
2025-09-30$1.85B129+28.79%+17.52%+11.27%+0.13B
2025-06-30$1.61B115+24.26%+14.94%+9.31%-0.21B
2025-03-31$1.53B101+9.21%+8.30%+0.91%-0.02B
2024-12-31$1.60B110+27.11%+24.89%+2.23%-0.06B
2024-09-30$1.59B109+37.04%+36.04%+1.00%+0.02B
2024-06-30$1.52B103+31.38%+24.49%+6.88%-0.02B
2024-03-31$1.47B107+35.61%+29.62%+5.99%+0.07B
2023-12-31$1.25B106+24.56%+26.18%-1.62%+0.15B
2023-09-30$971M91+15.48%+21.57%-6.08%+0.35B
2023-06-30$627M93+11.41%+19.42%-8.01%+0.08B
2023-03-31$506M91-9.60%-7.82%-1.79%+0.08B
2022-12-31$411M98-16.59%-18.17%+1.59%-0.06B
2022-09-30$454M97-11.53%-15.51%+3.97%+0.09B
2022-06-30$381M86+31.04%-10.62%+41.66%-0.55B