Main Street Research LLC — 13F Holdings & Portfolio

CIK 1513211 · latest 13F-HR filed 2026-04-30

Main Street Research LLC manages $1.72B in 13F-reported U.S. long-equity assets across 148 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are NVDA (6.30%), AAPL (5.96%), GOOGL (5.22%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 31 new positions, exited 12, added to 52, and trimmed 50.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

Loading holdings…
AUM

$1.72B

Long-equity book

Holdings

148

Distinct positions

Period

2026-03-31

Filed 2026-04-30

Q/Q Activity

+31 / −12 / ↑52 / ↓50

vs 2025-12-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • MICRON TECHNOLOGY INC$35.3M +2325.3%
  • SPDR SERIES TRUST$28.5M +64.9%
  • APPLE INC$23.3M +29.5%
  • ASML HLDG NV$12.1M +28.3%
  • GE VERNOVA INC$12.1M +37.7%
Show all 52

Top Trims

  • ROBINHOOD MKTS INC-$60.0M -99.6%
  • VISA INC-$58.0M -94.9%
  • MICROSOFT CORP-$56.3M -69.3%
  • PALANTIR TECHNOLOGIES INC-$53.7M -68.7%
  • UBER TECHNOLOGIES INC-$35.7M -97.7%
Show all 50

New Positions

  • CORNING INC$52.7M
  • BHP BILLITON LIMITED$37.8M
  • ASTRAZENECA PLC$37.6M
  • ROYAL BK CDA$36.0M
  • KEYSIGHT TECHNOLOGIES INC$31.9M
Show all 31

Exited Positions

  • ASTRAZENECA PLC$34.1M
  • ICICI BANK LIMITED$30.5M
  • BOOKING HOLDINGS INC$20.4M
  • VANGUARD SPECIALIZED FUNDS$518.9K
  • ISHARES TR$506.3K
Show all 12
All Holdings

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 NVIDIA CORPORATION NVDA 67066G104 $108.3M 6.30% 620,776 SH
2 APPLE INC AAPL 037833100 $102.4M 5.96% 403,578 SH
3 ALPHABET INC GOOGL 02079K305 $89.7M 5.22% 311,786 SH
4 ISHARES TR ISCF 46434V266 $81.9M 4.76% 1,958,627 SH
5 TAIWAN SEMICONDUCTOR MANUFAC TSM 874039100 $75.4M 4.39% 223,159 SH
6 SPDR SERIES TRUST XBI 78464A870 $72.5M 4.22% 567,479 SH
7 JPMORGAN CHASE & CO JPM 46625H100 $65.8M 3.83% 223,762 SH
8 BROADCOM INC AVGO 11135F101 $65.7M 3.83% 212,402 SH
9 MCKESSON CORP MCK 58155Q103 $58.6M 3.41% 67,774 SH
10 AMAZON COM INC AMZN 023135106 $56.1M 3.26% 269,193 SH
11 ASML HLDG NV ASML N07059210 $55.1M 3.20% 41,687 SH
12 CORNING INC GLW 219350105 $52.7M 3.07% 387,718 SH
13 COSTCO WHOLESALE CORPORATION COST 22160K105 $46.0M 2.68% 46,139 SH
14 JOHNSON & JOHNSON JNJ 478160104 $45.7M 2.66% 186,882 SH
15 ISHARES INC EWY 464286772 $44.5M 2.59% 361,874 SH
16 GE VERNOVA INC GEV 36828A101 $44.2M 2.57% 50,692 SH
17 WORLD GOLD TR GLDM 98149E303 $43.5M 2.53% 469,451 SH
18 CATERPILLAR INC CAT 149123101 $43.3M 2.52% 61,110 SH
19 WALMART INC WMT 931142103 $42.9M 2.49% 344,869 SH
20 CAMECO CORP CCJ 13321L108 $42.3M 2.46% 389,077 SH
21 META PLATFORMS INC META 30303M102 $40.6M 2.36% 70,962 SH
22 AMPHENOL CORP APH 032095101 $38.0M 2.21% 301,043 SH
23 BHP BILLITON LIMITED BHP 088606108 $37.8M 2.20% 519,212 SH
24 ASTRAZENECA PLC AZN G0593M107 $37.6M 2.19% 190,644 SH
25 MICRON TECHNOLOGY INC MU 595112103 $36.9M 2.14% 109,109 SH
26 ROYAL BK CDA RY 780087102 $36.0M 2.10% 222,568 SH
27 KEYSIGHT TECHNOLOGIES INC KEYS 49338L103 $31.9M 1.86% 112,937 SH
28 MICROSOFT CORP MSFT 594918104 $25.0M 1.45% 67,542 SH
29 PALANTIR TECHNOLOGIES INC PLTR 69608A108 $24.5M 1.43% 167,647 SH
30 PROCTER & GAMBLE CO PG 742718109 $21.9M 1.27% 151,627 SH
31 BARCLAYS PLC BCS 06738E204 $18.0M 1.05% 850,971 SH
32 FAIR ISAAC CORP FICO 303250104 $9.0M 0.53% 8,464 SH
33 ISHARES BITCOIN TRUST ETF IBIT 46438F101 $7.5M 0.44% 196,085 SH
34 ALPHABET INC GOOG 02079K107 $6.7M 0.39% 23,437 SH
35 BERKSHIRE HATHAWAY INC DEL BRK.B 084670702 $5.7M 0.33% 11,978 SH
36 PALO ALTO NETWORKS INC PANW 697435105 $5.5M 0.32% 34,024 SH
37 MCDONALDS CORP MCD 580135101 $4.8M 0.28% 15,483 SH
38 TESLA INC TSLA 88160R101 $4.6M 0.27% 12,337 SH
39 SCHWAB CHARLES CORP SCHW 808513105 $4.4M 0.25% 46,360 SH
40 ARISTA NETWORKS INC ANET 040413205 $4.3M 0.25% 34,981 SH
41 EXXON MOBIL CORP XOM 30231G102 $4.1M 0.24% 23,924 SH
42 WELLS FARGO & CO WFC 949746101 $3.7M 0.22% 46,882 SH
43 BERKSHIRE HATHAWAY INC DEL BRK.A 084670108 $3.6M 0.21% 5 SH
44 CHEVRON CORPORATION CVX 166764100 $3.5M 0.20% 16,851 SH
45 AUTODESK INC ADSK 052769106 $3.4M 0.20% 14,403 SH
46 ISHARES TR IXUS 46432F834 $3.3M 0.19% 38,583 SH
47 VISA INC V 92826C839 $3.1M 0.18% 10,246 SH
48 ELI LILLY & CO LLY 532457108 $2.7M 0.16% 2,908 SH
49 ISHARES INC URTH 464286392 $2.7M 0.15% 14,742 SH
50 ABBVIE INC ABBV 00287Y109 $2.2M 0.13% 10,258 SH
Filing History
Period Filed AUM Holdings Accession
2026-03-31 2026-04-30 $1.72B 148 0001420506-26-000773
2025-12-31 2026-02-09 $1.75B 129 0001420506-26-000210