Main Street Research LLC

Registered adviser

CIK

1513211

Location

SAUSALITO, CA

Portfolio Value

Mid $2,172,923,200

Diversification

Diversified

Filing Date

Global Rank

#1,461 / 8,807 ▲ 52

Top Industry

Semiconductors 23.6%

Period ended 4 months ago

Filed Jul 29, 2026 · 3mo

26 quarters · since Mar 2020

Regulatory profile

From Form ADV, the SEC filer profile, 13D/13G type codes and N-CEN, never from the name.

Holder type

Registered adviser

Form ADV roster, Oct 1, 2026

Form ADV adviser

CRD 114629

Roster of Oct 1, 2026

Regulatory AUM

$2,681,886,634

Main clients

Individuals and high net worth (98% of AUM)

Form ADV history

Monthly rosters from Dec 2019; each row is a run with the same figures, newest first.

Rosters	Regulatory AUM	Main clients
Apr 2026 to Oct 2026	$2,681,886,634	Individuals and high net worth (98%)
Apr 2025 to Mar 2026	$2,384,657,948	Individuals and high net worth (96%)
Feb 2024 to Mar 2025	$1,816,608,726	Individuals and high net worth (96%)
May 2023 to Jan 2024	$1,674,891,277	Individuals and high net worth (98%)
Apr 2023	$1,674,891,277	Individuals and high net worth (98%)
Apr 2022 to Mar 2023	$1,963,324,024	Individuals and high net worth (98%)

3 earlier changes not shown.

Portfolio style

Measured from the filed 13F common-share book for Jun 30, 2026, never from the firm's own description.

Style

Diversified active

Top 10 weight 53.1%, 25.6 effective positions, active share 61.8% against the S&P 500 as of 2026-06-30; it meets none of the index-like, systematic-like or concentrated tests

Turnover

Medium turnover

46.9% over the last four quarters (30% to under 100%)

Horizon

Long horizon

Value-weighted holding period 13.8 quarters (12+), a floor since 34.6% of the book was already held when coverage starts

Closest benchmark: the S&P 500 as of 2026-06-30, active share 61.8%; sector active share 18.8% against the combined 13F book's sector weights.

Over time 26 measured quarters

How the bands are measured

Style bands measure the filed 13F common-share book each closed quarter, tested in this order. Unknown: under $10,000,000 of valued equity or 5 stocks. Index-like (100+ stocks): active share of 20% or less against the closest benchmark, which is the S&P 500, S&P MidCap 400, S&P SmallCap 600, Russell 1000, Russell 2000, Nasdaq-100 or Dow Jones Industrial Average (weighted by an index-tracking fund's reported holdings or the index's constituents nearest the quarter end, over the names resolved to companies, and only when those are 90%+ of its weight) or every 13F filer's combined book, or index series holding 80%+ of the registered fund assets it advises (N-CEN) and equal to 50%+ of its book. Systematic-like: 500+ stocks, 100%+ annual turnover and a top 10 weight of 25% or less. Concentrated: a top 10 weight of 60%+ or 12 or fewer effective positions. Diversified active: none of these. Turnover is the smaller of buys and sells over average equity value, summed over four quarters: low under 30%, high 100%+. Horizon is the value-weighted number of quarters each position has been held: short under 4, long 12+.

Clone Performance

Build a hypothetical price-return history from this filer's public 13F holdings.

View clone backtest

Portfolio Concentration

140 tracked positions · as of Jun 30, 2026 · Δ vs Mar 31, 2026

Top Position

7.8%

+1.1 pts

Top 5

30.4%

+2.1 pts

Top 10

53.1%

+5.2 pts

HHI

391

Diversified+36

Portfolio Trend

26 quarters · across all stocks

Sector Breakdown

As of Jun 30, 2026

Sector	% Portfolio	Value	Positions
Technology	44.3%	$963,099,449	37
Unclassified	12.5%	$272,440,387	25
Financial Services	8.8%	$191,055,278	17
Communication Services	7.5%	$163,371,091	7
Industrials	6.0%	$131,425,073	12
Healthcare	5.4%	$116,445,008	16
Consumer Defensive	5.0%	$109,019,425	9
Consumer Cyclical	5.0%	$108,750,253	10
Energy	3.4%	$73,281,008	5
Basic Materials	2.0%	$44,036,228	2

Last Quarter's Activity

Export CSV

Jun 30, 2026 vs Mar 31, 2026

Added To

Positions the filer increased

25 positions

Ticker	Company	Δ Shares	Shares	Value
BCS	Barclays PLC	+770,519	1,621,490	$43,553,221
ISCF	iShares International Small-Cap Equity Factor ETF	+68,729	2,027,356	$87,764,241
NVDA	Nvidia Corp	+9,277	630,053	$126,067,304
XBI	State Street(R) SPDR(R) S&P(R) Biotech ETF	+9,275	576,754	$91,271,320
BHP	BHP Group Ltd	+8,839	528,051	$43,991,928
APH	Amphenol Corp /De/	+7,673	308,716	$108,865,610
AZN	Astrazeneca PLC	+6,773	197,417	$37,434,211
GLW	Corning Inc /Ny	+6,340	394,058	$100,654,234
AMZN	Amazon Com Inc	+5,545	274,738	$65,481,054
TSM	Taiwan Semiconductor Manufacturing Co Ltd	+5,270	228,429	$109,090,837
GOOGL	Alphabet Inc.	+5,161	316,947	$113,267,349
RY	Royal Bank Of Canada	+4,568	227,136	$47,010,337
WMT	Walmart Inc.	+3,781	348,650	$39,488,099
AAPL	Apple Inc.	+2,551	406,129	$117,517,487
JPM	Jpmorgan Chase & Co	+2,537	226,299	$74,074,451
CCJ	Cameco Corp	+2,452	391,529	$39,881,143
MUFG	Mitsubishi Ufj Financial Group Inc	+2,273	32,721	$650,820
KEYS	Keysight Technologies, Inc.	+2,171	115,108	$40,295,857
SCHI	Schwab 5-10 Year Corporate Bond ETF	+2,162	46,488	$1,052,488
IWF	iShares Russell 1000 Growth ETF	+2,085	2,780	$345,192
JNJ	Johnson & Johnson	+1,758	188,640	$47,908,900
MTCH	Match Group, Inc.	+1,735	8,746	$332,785
WFC	Wells Fargo & Company/Mn	+1,660	48,542	$4,011,510
MSFT	Microsoft Corp	+1,640	69,182	$25,806,269
AVGO	Broadcom Inc.	+1,439	213,841	$80,778,437
No positions match the current search.

Trimmed

Positions the filer reduced

25 positions

Ticker	Company	Δ Shares	Shares	Value
PLTR	Palantir Technologies Inc.	−156,203	11,444	$1,335,171
MCK	Mckesson Corp	−39,299	28,475	$21,515,710
PANW	Palo Alto Networks Inc	−10,681	23,343	$7,960,429
MCD	Mcdonalds Corp	−6,570	8,913	$2,409,273
T	At&T Inc.	−6,122	14,071	$291,269
CMCSA	Comcast Corp	−2,483	11,037	$270,958
UNP	Union Pacific Corp	−1,716	2,413	$656,336
BMY	Bristol Myers Squibb Co	−1,690	5,252	$302,620
XOM	ExxonMobil Holdings Corp	−1,487	22,437	$3,067,586
ABT	Abbott Laboratories	−1,366	2,493	$226,214
URTH	iShares MSCI World ETF	−1,231	13,511	$2,737,869
MRK	Merck & Co., Inc.	−1,223	8,298	$1,066,293
CRM	Salesforce, Inc.	−1,122	5,802	$908,941
EWY	iShares Trust	−1,009	360,865	$72,858,643
V	Visa Inc.	−877	9,369	$3,214,410
SCHX	Schwab U.S. Large-Cap ETF	−800	9,835	$289,444
CVX	Chevron Corp	−771	16,080	$2,665,420
IVV	iShares Core S&P 500 ETF	−744	1,810	$1,355,490
GOOG	Alphabet Inc.	−730	22,707	$8,023,064
HOOD	Robinhood Markets, Inc.	−709	2,581	$258,822
UBER	Uber Technologies, Inc	−685	10,806	$779,760
CLX	Clorox Co /De/	−603	8,934	$852,660
SCHF	Schwab International Equity ETF	−600	9,606	$266,086
XYL	Xylem Inc.	−590	2,729	$322,595
PG	PROCTER & GAMBLE Co	−554	151,073	$22,153,344
No positions match the current search.

New Positions

Positions the filer opened this quarter

13 positions

Ticker	Company	Shares	Value
ROST	Ross Stores, Inc.	150,755	$32,088,201
FTI	TechnipFMC plc	413,657	$27,425,459
HUT	Hut 8 Corp.	3,986	$460,163
UAL	United Airlines Holdings, Inc.	2,344	$318,760
VEA	Vanguard FTSE Developed Markets ETF	4,086	$291,127
MNST	Monster Beverage Corp	2,967	$285,188
IUSG	iShares Core S&P U.S. Growth ETF	1,435	$269,909
IUSV	iShares Core S&P U.S. Value ETF	2,371	$261,165
QCOM	Qualcomm Inc/De	1,375	$254,086
ABEO	Abeona Therapeutics Inc.	38,514	$238,016
HIMS	Hims & Hers Health, Inc.	6,200	$214,954
KO	Coca Cola Co	2,558	$207,888
DDOG	Datadog, Inc.	791	$205,944
No positions match the current search.

Sold Out

Positions the filer fully exited

21 positions

Ticker	Company	Shares	Value
GLDM	World Gold Trust	469,451	$43,513,413
IBIT	iShares Bitcoin Trust ETF	196,085	$7,533,585
DIS	Walt Disney Co	10,730	$1,034,157
GLD	Spdr Gold Trust	1,806	$777,103
ISRG	Intuitive Surgical Inc	839	$386,770
BSX	Boston Scientific Corp	5,993	$376,060
ACN	Accenture plc	1,683	$333,722
INTU	Intuit Inc.	712	$307,854
COIN	Coinbase Global, Inc.	1,550	$270,645
COP	Conocophillips	1,950	$257,400
NFLX	Netflix Inc	2,673	$257,008
MA	Mastercard Inc	493	$246,332
ADBE	Adobe Inc.	1,005	$244,295
AXP	American Express Co	773	$233,817
HD	Home Depot, Inc.	686	$225,618
TMUS	T-Mobile US, Inc.	1,070	$224,732
COF	Capital One Financial Corp	1,180	$215,267
NEE	Nextera Energy Inc	2,266	$210,466
TDY	Teledyne Technologies Inc	338	$204,493
VRT	Vertiv Holdings Co	810	$202,969
OMDA	Omada Health, Inc.	15,909	$199,976
No positions match the current search.

Portfolio Positions

Compact Export CSV View 13F filing

140 tracked positions · $2,172,923,200 total · filing declares 140 positions · $2,118,491,302 · as of Jun 30, 2026

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

Showing 1–50 of 140 positions by value · page 1 of 3

Ticker	Company	Type	Shares	Δ Shares	Value (USD)	% Δ Value	Held (qtrs)	Est. cost/share	% of Portfolio
NVDA	Nvidia Corp Technology	Added	630,053	+9,277	$126,067,304	+16.4%	26+	before history	5.80%
MU	Micron Technology Inc Technology	Reduced	108,636	-473	$125,397,448	+240.2%	5	$377.18	5.77%
AAPL	Apple Inc. Technology	Added	406,129	+2,551	$117,517,487	+14.7%	26+	before history	5.41%
GOOGL	Alphabet Inc. Communication Services	Added	316,947	+5,161	$113,267,349	+26.3%	26+	before history	5.21%
TSM	Taiwan Semiconductor Manufacturing Co Ltd Technology	Added	228,429	+5,270	$109,090,837	+44.7%	9	$196.50	5.02%
APH	Amphenol Corp /De/ Technology	Added	308,716	+7,673	$108,865,610	+43.1%	4	unpriced	5.01%
GLW	Corning Inc /Ny Technology	Added	394,058	+6,340	$100,654,234	+90.9%	2	$121.59	4.63%
XBI	State Street(R) SPDR(R) S&P(R) Biotech ETF	Added	576,754	+9,275	$91,271,320	+25.9%	3	$118.64	4.20%
ISCF	iShares International Small-Cap Equity Factor ETF	Added	2,027,356	+68,729	$87,764,241	—	4	unpriced	4.04%
ASML	Asml Holding NV Technology	Added	42,396	+709	$84,344,294	+53.2%	26+	before history	3.88%
AVGO	Broadcom Inc. Technology	Added	213,841	+1,439	$80,778,437	+22.9%	25	before history	3.72%
JPM	Jpmorgan Chase & Co Financial Services	Added	226,299	+2,537	$74,074,451	+12.5%	13	$160.43	3.41%
EWY	iShares Trust	Reduced	360,865	-1,009	$72,858,643	—	3	unpriced	3.35%
CAT	Caterpillar Inc Industrials	Added	61,759	+649	$65,767,159	+51.9%	25	before history	3.03%
AMZN	Amazon Com Inc Consumer Cyclical	Added	274,738	+5,545	$65,481,054	+16.8%	26+	before history	3.01%
GEV	GE Vernova Inc. Industrials	Added	50,802	+110	$59,685,237	+34.9%	6	$472.30	2.75%
JNJ	Johnson & Johnson Healthcare	Added	188,640	+1,758	$47,908,900	+4.9%	26+	before history	2.20%
RY	Royal Bank Of Canada Financial Services	Added	227,136	+4,568	$47,010,337	+30.6%	2	$167.67	2.16%
COST	Costco Wholesale Corp /New Consumer Defensive	Added	47,497	+1,358	$44,432,018	−3.4%	26+	before history	2.04%
BHP	BHP Group Ltd Basic Materials	Added	528,051	+8,839	$43,991,928	+16.5%	2	$70.87	2.02%
BCS	Barclays PLC Financial Services	Added	1,621,490	+770,519	$43,553,221	+141.9%	4	$21.85	2.00%
META	Meta Platforms, Inc. Communication Services	Added	72,187	+1,225	$40,662,215	+0.2%	13	$455.41	1.87%
KEYS	Keysight Technologies, Inc. Technology	Added	115,108	+2,171	$40,295,857	+26.4%	2	$252.22	1.85%
CCJ	Cameco Corp Energy	Added	391,529	+2,452	$39,881,143	−5.6%	4	$79.00	1.84%
WMT	Walmart Inc. Consumer Defensive	Added	348,650	+3,781	$39,488,099	−7.9%	26+	before history	1.82%
AZN	Astrazeneca PLC Healthcare	Added	197,417	+6,773	$37,434,211	−0.4%	2	unpriced	1.72%
ROST	Ross Stores, Inc. Consumer Cyclical	NEW	150,755	NEW	$32,088,201	NEW	1	$225.00	1.48%
FTI	TechnipFMC plc Energy	NEW	413,657	NEW	$27,425,459	NEW	1	$70.80	1.26%
MSFT	Microsoft Corp Technology	Added	69,182	+1,640	$25,806,269	+3.2%	26+	before history	1.19%
PG	PROCTER & GAMBLE Co Consumer Defensive	Reduced	151,073	-554	$22,153,344	+1.2%	26+	before history	1.02%
MCK	Mckesson Corp Healthcare	Reduced	28,475	-39,299	$21,515,710	−63.3%	18	$292.49	0.99%
FICO	Fair Isaac Corp Technology	Added	9,580	+1,116	$11,445,992	+26.7%	26+	before history	0.53%
GOOG	Alphabet Inc. Communication Services	Reduced	22,707	-730	$8,023,064	+19.3%	26+	before history	0.37%
PANW	Palo Alto Networks Inc Technology	Reduced	23,343	-10,681	$7,960,429	+45.9%	16	unpriced	0.37%
BRK-B	Berkshire Hathaway Inc Financial Services	Added	11,980	+2	$5,994,672	+4.4%	26+	before history	0.28%
ANET	Arista Networks, Inc. Technology	Reduced	34,937	-44	$5,935,097	+38.2%	2	$133.77	0.27%
TSLA	Tesla, Inc. Consumer Cyclical	Added	12,943	+606	$5,443,825	+18.7%	26+	before history	0.25%
SCHW	Schwab Charles Corp Financial Services	Reduced	45,887	-473	$4,233,993	−2.8%	26+	before history	0.19%
WFC	Wells Fargo & Company/Mn Financial Services	Added	48,542	+1,660	$4,011,510	+7.5%	26+	before history	0.18%
BRK-A	Berkshire Hathaway Inc Financial Services	Held	5	0	$3,744,250	+4.3%	17	$506,234.50	0.17%
IXUS	iShares Core MSCI Total International Stock ETF	Added	39,073	+490	$3,729,127	—	5	unpriced	0.17%
LLY	ELI LILLY & Co Healthcare	Reduced	2,746	-162	$3,293,635	+23.1%	23	$631.48	0.15%
V	Visa Inc. Financial Services	Reduced	9,369	-877	$3,214,410	+3.8%	26+	before history	0.15%
XOM	ExxonMobil Holdings Corp Energy	Reduced	22,437	-1,487	$3,067,586	−24.4%	26+	before history	0.14%
ADSK	Autodesk, Inc. Technology	Reduced	14,240	-163	$2,768,540	−19.7%	26+	before history	0.13%
URTH	iShares MSCI World ETF	Reduced	13,511	-1,231	$2,737,869	+3.2%	13	$129.49	0.13%
CVX	Chevron Corp Energy	Reduced	16,080	-771	$2,665,420	−23.5%	26+	before history	0.12%
SPY	Spdr S&P 500 ETF Trust	Added	3,485	+222	$2,602,493	+22.6%	26+	before history	0.12%
ABBV	AbbVie Inc. Healthcare	Reduced	9,721	-537	$2,446,192	+9.6%	26+	before history	0.11%
MCD	Mcdonalds Corp Consumer Cyclical	Reduced	8,913	-6,570	$2,409,273	−49.9%	26+	before history	0.11%

Showing the top 50 of 140 positions. Create a free account to see every position, past quarters, search, filters and CSV export.

Covers the securities this platform tracks: U.S.-listed common stock and the put/call positions reported on it. A 13F can also report security types outside that coverage — preferred shares, bonds, warrants, untracked share classes — so the filing's own declared total can exceed the figures above. The source filing is linked at the top of this table.