Main Street Research LLC — 13F Holdings & Portfolio
CIK 1513211 · latest 13F-HR filed 2026-07-29
Main Street Research LLC manages $2.12B in 13F-reported U.S. long-equity assets across 140 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are NVDA (5.95%), MU (5.92%), AAPL (5.55%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 13 new positions, exited 21, added to 80, and trimmed 27.
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.
LAKEVILLE, CT 06039
$2.12B
Long-equity book
140
Distinct positions
2026-06-30
Filed 2026-07-29
+13 / −21 / ↑80 / ↓27
vs 2026-03-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- MICRON TECHNOLOGY INC$88.5M +240.2%
- CORNING INC$47.9M +90.9%
- TAIWAN SEMICONDUCTOR MANUFAC$33.7M +44.7%
- ASML HLDG NV$29.3M +53.2%
- ISHARES INC$28.3M +63.7%
Top Trims
- MCKESSON CORP-$37.1M -63.3%
- PALANTIR TECHNOLOGIES INC-$23.2M -94.6%
- WALMART INC-$3.4M -7.9%
- MCDONALDS CORP-$2.4M -49.9%
- CAMECO CORP-$2.4M -5.6%
New Positions
- ROSS STORES INC$32.1M
- TECHNIPFMC PLC$27.4M
- HUT 8 CORP$460.2K
- UNITED AIRLS HLDGS INC$318.8K
- VANGUARD TAX-MANAGED FDS$291.1K
Exited Positions
- WORLD GOLD TR$43.5M
- ISHARES BITCOIN TRUST ETF$7.5M
- DISNEY WALT CO$1.0M
- SPDR GOLD TR$777.1K
- INTUITIVE SURGICAL INC$386.8K
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 | $126.1M | 5.95% | 630,053 | SH |
| 2 | MICRON TECHNOLOGY INC | MU | 595112103 | $125.4M | 5.92% | 108,636 | SH |
| 3 | APPLE INC | AAPL | 037833100 | $117.5M | 5.55% | 406,129 | SH |
| 4 | ALPHABET INC | GOOGL | 02079K305 | $113.3M | 5.35% | 316,947 | SH |
| 5 | TAIWAN SEMICONDUCTOR MANUFAC | TSM | 874039100 | $109.1M | 5.15% | 228,429 | SH |
| 6 | CORNING INC | GLW | 219350105 | $100.7M | 4.75% | 394,058 | SH |
| 7 | SPDR SERIES TRUST | XBI | 78464A870 | $91.3M | 4.31% | 576,754 | SH |
| 8 | ISHARES TR | ISCF | 46434V266 | $87.8M | 4.14% | 2,027,356 | SH |
| 9 | ASML HLDG NV | ASML | N07059210 | $84.3M | 3.98% | 42,396 | SH |
| 10 | BROADCOM INC | AVGO | 11135F101 | $80.8M | 3.81% | 213,841 | SH |
| 11 | JPMORGAN CHASE & CO | JPM | 46625H100 | $74.1M | 3.50% | 226,299 | SH |
| 12 | ISHARES INC | EWY | 464286772 | $72.9M | 3.44% | 360,865 | SH |
| 13 | CATERPILLAR INC | CAT | 149123101 | $65.8M | 3.10% | 61,759 | SH |
| 14 | AMAZON COM INC | AMZN | 023135106 | $65.5M | 3.09% | 274,738 | SH |
| 15 | GE VERNOVA INC | GEV | 36828A101 | $59.7M | 2.82% | 50,802 | SH |
| 16 | AMPHENOL CORP | APH | 032095101 | $54.4M | 2.57% | 308,716 | SH |
| 17 | JOHNSON & JOHNSON | JNJ | 478160104 | $47.9M | 2.26% | 188,640 | SH |
| 18 | ROYAL BK CDA | RY | 780087102 | $47.0M | 2.22% | 227,136 | SH |
| 19 | COSTCO WHOLESALE CORPORATION | COST | 22160K105 | $44.4M | 2.10% | 47,497 | SH |
| 20 | BHP BILLITON LIMITED | BHP | 088606108 | $44.0M | 2.08% | 528,051 | SH |
| 21 | BARCLAYS PLC | BCS | 06738E204 | $43.6M | 2.06% | 1,621,490 | SH |
| 22 | META PLATFORMS INC | META | 30303M102 | $40.7M | 1.92% | 72,187 | SH |
| 23 | KEYSIGHT TECHNOLOGIES INC | KEYS | 49338L103 | $40.3M | 1.90% | 115,108 | SH |
| 24 | CAMECO CORP | CCJ | 13321L108 | $39.9M | 1.88% | 391,529 | SH |
| 25 | WALMART INC | WMT | 931142103 | $39.5M | 1.86% | 348,650 | SH |
| 26 | ASTRAZENECA PLC | AZN | G0593M107 | $37.4M | 1.77% | 197,417 | SH |
| 27 | ROSS STORES INC | ROST | 778296103 | $32.1M | 1.51% | 150,755 | SH |
| 28 | TECHNIPFMC PLC | FTI | G87110105 | $27.4M | 1.29% | 413,657 | SH |
| 29 | MICROSOFT CORP | MSFT | 594918104 | $25.8M | 1.22% | 69,182 | SH |
| 30 | PROCTER & GAMBLE CO | PG | 742718109 | $22.2M | 1.05% | 151,073 | SH |
| 31 | MCKESSON CORP | MCK | 58155Q103 | $21.5M | 1.02% | 28,475 | SH |
| 32 | FAIR ISAAC CORP | FICO | 303250104 | $11.4M | 0.54% | 9,580 | SH |
| 33 | ALPHABET INC | GOOG | 02079K107 | $8.0M | 0.38% | 22,707 | SH |
| 34 | PALO ALTO NETWORKS INC | PANW | 697435105 | $8.0M | 0.38% | 23,343 | SH |
| 35 | BERKSHIRE HATHAWAY INC DEL | BRK.B | 084670702 | $6.0M | 0.28% | 11,980 | SH |
| 36 | ARISTA NETWORKS INC | ANET | 040413205 | $5.9M | 0.28% | 34,937 | SH |
| 37 | TESLA INC | TSLA | 88160R101 | $5.4M | 0.26% | 12,943 | SH |
| 38 | SCHWAB CHARLES CORP | SCHW | 808513105 | $4.2M | 0.20% | 45,887 | SH |
| 39 | WELLS FARGO & CO | WFC | 949746101 | $4.0M | 0.19% | 48,542 | SH |
| 40 | BERKSHIRE HATHAWAY INC DEL | BRK.A | 084670108 | $3.7M | 0.18% | 5 | SH |
| 41 | ISHARES TR | IXUS | 46432F834 | $3.7M | 0.18% | 39,073 | SH |
| 42 | ELI LILLY & CO | LLY | 532457108 | $3.3M | 0.16% | 2,746 | SH |
| 43 | VISA INC | V | 92826C839 | $3.2M | 0.15% | 9,369 | SH |
| 44 | EXXON MOBIL CORP | XOM | 30231G102 | $3.1M | 0.14% | 22,437 | SH |
| 45 | AUTODESK INC | ADSK | 052769106 | $2.8M | 0.13% | 14,240 | SH |
| 46 | ISHARES INC | URTH | 464286392 | $2.7M | 0.13% | 13,511 | SH |
| 47 | CHEVRON CORPORATION | CVX | 166764100 | $2.7M | 0.13% | 16,080 | SH |
| 48 | STATE STR SPDR S&P 500 ETF T | SPY | 78462F103 | $2.6M | 0.12% | 3,485 | SH |
| 49 | ABBVIE INC | ABBV | 00287Y109 | $2.4M | 0.12% | 9,721 | SH |
| 50 | MCDONALDS CORP | MCD | 580135101 | $2.4M | 0.11% | 8,913 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-07-29 | $2.12B | 140 | 0001420506-26-001335 |
| 2026-03-31 | 2026-04-30 | $1.72B | 148 | 0001420506-26-000773 |
| 2025-12-31 | 2026-02-09 | $1.75B | 129 | 0001420506-26-000210 |