Main Street Research LLC

CIK

1513211

Location

SAUSALITO, CA

Portfolio Value

Mid $1,495,060,876

Diversification

Diversified

Filing Date

Global Rank

#1,406 / 8,604 ▲ 9 · as of Mar 2026

Top Industry

Semiconductors 20.1%

3Y Alpha vs SPY

-0.1%

Period ended 3 months ago

Filed Apr 30, 2026 · 2mo

25 quarters · since Mar 2020

Clone Performance

Jul 2023–Jul 2026 · vs SPY

Hypothetical growth of cloning every reported 13F position and rebalancing on each filing, indexed to the same start.

Cloned portfolio

+77.5%

SPY

+76.5%

Annualised alpha

+0.2%

Max drawdown

−19.8%

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

127 positions · as of Mar 31, 2026 · Δ vs Dec 31, 2025

Top Position

7.2%

−0.0 pts

Top 5

29.5%

+0.6 pts

Top 10

48.8%

−1.6 pts

HHI

369

Diversified−19

Portfolio Trend

25 quarters · across all stocks

Sector Breakdown

As of Mar 31, 2026

Sector	% Portfolio	Value	Positions
Technology	43.4%	$649,134,579	39
Healthcare	10.1%	$151,642,767	17
Financial Services	9.5%	$141,870,366	19
Communication Services	8.9%	$133,418,703	9
Consumer Defensive	7.6%	$113,215,399	7
Industrials	6.2%	$93,365,243	12
Consumer Cyclical	4.6%	$68,379,206	10
Unclassified	3.7%	$55,662,902	6
Energy	3.4%	$50,347,065	5
Basic Materials	2.5%	$37,814,180	2
Utilities	0.0%	$210,466	1

Last Quarter's Activity

Export CSV

Mar 31, 2026 vs Dec 31, 2025

Added To

Positions the filer increased

25 positions

Ticker	Company	Δ Shares	Shares	Value
AAPL	Apple Inc.	+112,641	403,578	$102,424,060
MU	Micron Technology Inc	+103,786	109,109	$36,861,384
WFC	Wells Fargo & Company/Mn	+27,036	46,882	$3,732,276
NVDA	Nvidia Corp	+24,932	620,776	$108,263,334
PANW	Palo Alto Networks Inc	+20,789	34,024	$5,454,727
IBIT	iShares Bitcoin Trust ETF	+16,545	196,085	$7,533,585
SCHW	Schwab Charles Corp	+14,578	46,360	$4,356,912
GOOGL	Alphabet Inc.	+14,242	311,786	$89,657,182
AMZN	Amazon Com Inc	+9,344	269,193	$56,064,826
JNJ	Johnson & Johnson	+7,564	186,882	$45,681,436
CVX	Chevron Corp	+7,331	16,851	$3,486,471
CCJ	Cameco Corp	+7,209	389,077	$42,257,652
GLDM	World Gold Trust	+7,135	469,451	$43,513,413
AVGO	Broadcom Inc.	+7,007	212,402	$65,740,543
WMT	Walmart Inc.	+6,474	344,869	$42,860,319
T	At&T Inc.	+6,279	20,193	$585,395
FICO	Fair Isaac Corp	+5,972	8,464	$9,035,658
APH	Amphenol Corp /De/	+5,686	301,043	$38,036,783
TSM	Taiwan Semiconductor Manufacturing Co Ltd	+5,012	223,159	$75,416,584
CMCSA	Comcast Corp	+2,608	13,520	$388,159
JPM	Jpmorgan Chase & Co	+1,843	223,762	$65,821,829
UNP	Union Pacific Corp	+1,787	4,129	$1,001,777
MRK	Merck & Co., Inc.	+1,737	9,521	$1,145,281
TXN	Texas Instruments Inc	+1,685	3,527	$684,731
PEP	Pepsico Inc	+1,606	3,722	$577,989
No positions match the current search.

Trimmed

Positions the filer reduced

25 positions

Ticker	Company	Δ Shares	Shares	Value
BCS	Barclays PLC	−831,866	850,971	$18,006,546
HOOD	Robinhood Markets, Inc.	−529,109	3,290	$227,997
UBER	Uber Technologies, Inc	−435,414	11,491	$826,547
PLTR	Palantir Technologies Inc.	−272,603	167,647	$24,523,403
V	Visa Inc.	−163,842	10,246	$3,096,751
MSFT	Microsoft Corp	−100,665	67,542	$25,002,022
COST	Costco Wholesale Corp /New	−16,227	46,139	$45,974,283
META	Meta Platforms, Inc.	−15,585	70,962	$40,599,489
NFLX	Netflix Inc	−7,948	2,673	$257,008
BMY	Bristol Myers Squibb Co	−7,678	6,942	$421,032
MCD	Mcdonalds Corp	−3,105	15,483	$4,811,961
TMUS	T-Mobile US, Inc.	−1,092	1,070	$224,732
INTC	Intel Corp	−950	5,919	$261,205
NEE	Nextera Energy Inc	−529	2,266	$210,466
SJM	J M SMUCKER Co	−472	2,858	$275,625
TSLA	Tesla, Inc.	−411	12,337	$4,586,279
ACN	Accenture plc	−376	1,683	$333,722
AMD	Advanced Micro Devices Inc	−277	3,145	$639,787
HD	Home Depot, Inc.	−276	686	$225,618
TMO	Thermo Fisher Scientific Inc.	−251	900	$442,377
NSC	Norfolk Southern Corp	−240	877	$251,699
AON	Aon plc	−199	622	$200,769
MMM	3M Co	−189	7,870	$1,142,960
BRK-B	Berkshire Hathaway Inc	−138	11,978	$5,739,857
SYK	Stryker Corp	−80	1,763	$579,304
No positions match the current search.

New Positions

Positions the filer opened this quarter

25 positions

Ticker	Company	Shares	Value
GLW	Corning Inc /Ny	387,718	$52,718,016
BHP	BHP Group Ltd	519,212	$37,767,480
AZN	Astrazeneca PLC	190,644	$37,598,809
RY	Royal Bank Of Canada	222,568	$36,007,051
KEYS	Keysight Technologies, Inc.	112,937	$31,890,020
ANET	Arista Networks, Inc.	34,981	$4,294,967
DIS	Walt Disney Co	10,730	$1,034,157
PHM	Pultegroup Inc/Mi/	7,382	$868,197
CRUS	Cirrus Logic, Inc.	5,734	$829,251
GS	Goldman Sachs Group Inc	874	$739,395
ON	On Semiconductor Corp	10,350	$640,872
BX	Blackstone Inc.	5,317	$611,401
DHI	Horton D R Inc /De/	3,808	$522,533
PTC	Ptc Inc.	2,481	$353,517
LEN	Lennar Corp /New/	3,904	$339,023
IT	Gartner Inc	2,115	$334,889
FTNT	Fortinet, Inc.	4,075	$333,009
LNG	Cheniere Energy, Inc.	1,010	$286,597
COP	Conocophillips	1,950	$257,400
IDXX	Idexx Laboratories Inc /De	447	$251,164
ENTG	Entegris Inc	1,852	$217,128
MTCH	Match Group, Inc.	7,011	$215,307
CI	Cigna Group	771	$205,664
TDY	Teledyne Technologies Inc	338	$204,493
PHG	Koninklijke Philips NV	7,420	$203,308
No positions match the current search.

Sold Out

Positions the filer fully exited

9 positions

Ticker	Company	Shares	Value
IBN	Icici Bank Ltd	1,022,131	$30,459,503
BKNG	Booking Holdings Inc.	3,807	$20,387,741
HUT	Hut 8 Corp.	8,986	$412,816
TRMB	Trimble Inc.	3,762	$294,752
LIN	Linde PLC	600	$255,834
IBM	International Business Machines Corp	848	$251,186
GILD	Gilead Sciences, Inc.	1,829	$224,491
BN	BROOKFIELD Corp /ON/	4,628	$212,378
HIMS	Hims & Hers Health, Inc.	6,200	$201,314
No positions match the current search.

Portfolio Positions

Compact Export CSV View 13F filing

127 positions · $1,495,060,876 total · as of Mar 31, 2026

All sectors Basic Materials Communication Services Consumer Cyclical Consumer Defensive Energy Financial Services Healthcare Industrials Technology Utilities

Showing 1–50 of 127 positions by value · page 1 of 3

Ticker	Company	Type	Shares	Δ Shares	Value (USD)	% Δ Value	% of Portfolio
NVDA	Nvidia Corp Technology	Added	620,776	+24,932	$108,263,334	−2.6%	7.24%
AAPL	Apple Inc. Technology	Added	403,578	+112,641	$102,424,060	+29.5%	6.85%
GOOGL	Alphabet Inc. Communication Services	Added	311,786	+14,242	$89,657,182	−3.7%	6.00%
TSM	Taiwan Semiconductor Manufacturing Co Ltd Technology	Added	223,159	+5,012	$75,416,584	+13.8%	5.04%
JPM	Jpmorgan Chase & Co Financial Services	Added	223,762	+1,843	$65,821,829	−8.0%	4.40%
AVGO	Broadcom Inc. Technology	Added	212,402	+7,007	$65,740,543	−7.5%	4.40%
MCK	Mckesson Corp Healthcare	Added	67,774	+413	$58,648,908	+6.1%	3.92%
AMZN	Amazon Com Inc Consumer Cyclical	Added	269,193	+9,344	$56,064,826	−6.5%	3.75%
ASML	Asml Holding NV Technology	Added	41,687	+1,569	$55,061,440	+28.3%	3.68%
GLW	Corning Inc /Ny Technology	NEW	387,718	NEW	$52,718,016	NEW	3.53%
COST	Costco Wholesale Corp /New Consumer Defensive	Reduced	46,139	-16,227	$45,974,283	−14.5%	3.08%
JNJ	Johnson & Johnson Healthcare	Added	186,882	+7,564	$45,681,436	+23.1%	3.06%
GEV	GE Vernova Inc. Industrials	Added	50,692	+1,531	$44,249,046	+37.7%	2.96%
GLDM	World Gold Trust	Added	469,451	+7,135	$43,513,413	+10.3%	2.91%
CAT	Caterpillar Inc Industrials	Added	61,110	+1,551	$43,293,990	+26.9%	2.90%
WMT	Walmart Inc. Consumer Defensive	Added	344,869	+6,474	$42,860,319	+13.7%	2.87%
CCJ	Cameco Corp Energy	Added	389,077	+7,209	$42,257,652	+21.0%	2.83%
META	Meta Platforms, Inc. Communication Services	Reduced	70,962	-15,585	$40,599,489	−28.9%	2.72%
APH	Amphenol Corp /De/ Technology	Added	301,043	+5,686	$38,036,783	−4.7%	2.54%
BHP	BHP Group Ltd Basic Materials	NEW	519,212	NEW	$37,767,480	NEW	2.53%
AZN	Astrazeneca PLC Healthcare	NEW	190,644	NEW	$37,598,809	NEW	2.51%
MU	Micron Technology Inc Technology	Added	109,109	+103,786	$36,861,384	+2326.3%	2.47%
RY	Royal Bank Of Canada Financial Services	NEW	222,568	NEW	$36,007,051	NEW	2.41%
KEYS	Keysight Technologies, Inc. Technology	NEW	112,937	NEW	$31,890,020	NEW	2.13%
MSFT	Microsoft Corp Technology	Reduced	67,542	-100,665	$25,002,022	−69.3%	1.67%
PLTR	Palantir Technologies Inc. Technology	Reduced	167,647	-272,603	$24,523,403	−68.7%	1.64%
PG	PROCTER & GAMBLE Co Consumer Defensive	Added	151,627	+543	$21,901,003	+1.2%	1.46%
BCS	Barclays PLC Financial Services	Reduced	850,971	-831,866	$18,006,546	−58.0%	1.20%
FICO	Fair Isaac Corp Technology	Added	8,464	+5,972	$9,035,658	+114.5%	0.60%
IBIT	iShares Bitcoin Trust ETF	Added	196,085	+16,545	$7,533,585	−15.5%	0.50%
BRK-B	Berkshire Hathaway Inc Financial Services	Reduced	11,978	-138	$5,739,857	−5.8%	0.38%
PANW	Palo Alto Networks Inc Technology	Added	34,024	+20,789	$5,454,727	+123.7%	0.36%
MCD	Mcdonalds Corp Consumer Cyclical	Reduced	15,483	-3,105	$4,811,961	−15.3%	0.32%
TSLA	Tesla, Inc. Consumer Cyclical	Reduced	12,337	-411	$4,586,279	−20.0%	0.31%
SCHW	Schwab Charles Corp Financial Services	Added	46,360	+14,578	$4,356,912	+37.2%	0.29%
ANET	Arista Networks, Inc. Technology	NEW	34,981	NEW	$4,294,967	NEW	0.29%
XOM	Exxon Mobil Corp Energy	Added	23,924	+715	$4,058,945	+45.3%	0.27%
WFC	Wells Fargo & Company/Mn Financial Services	Added	46,882	+27,036	$3,732,276	+101.8%	0.25%
CVX	Chevron Corp Energy	Added	16,851	+7,331	$3,486,471	+140.3%	0.23%
ADSK	Autodesk, Inc. Technology	Added	14,403	+112	$3,448,078	−18.5%	0.23%
V	Visa Inc. Financial Services	Reduced	10,246	-163,842	$3,096,751	−94.9%	0.21%
LLY	ELI LILLY & Co Healthcare	Added	2,908	+1,489	$2,674,691	+75.4%	0.18%
ABBV	AbbVie Inc. Healthcare	Added	10,258	+903	$2,231,012	+4.4%	0.15%
SPY	Spdr S&P 500 ETF Trust	Added	3,263	+600	$2,122,059	+16.9%	0.14%
CRM	Salesforce, Inc. Technology	Added	6,924	+560	$1,292,503	−23.3%	0.09%
RTX	RTX Corp Industrials	Added	6,066	+570	$1,170,131	+16.1%	0.08%
MRK	Merck & Co., Inc. Healthcare	Added	9,521	+1,737	$1,145,281	+39.8%	0.08%
MMM	3M Co Industrials	Reduced	7,870	-189	$1,142,960	−11.4%	0.08%
DIS	Walt Disney Co Communication Services	NEW	10,730	NEW	$1,034,157	NEW	0.07%
QQQ	Invesco Qqq Trust, Series 1	Added	1,769	+424	$1,021,031	+23.6%	0.07%