Terminal · Institutions

Every 13F-reported equity position this quarter, with its quarter-over-quarter change — each row traces back to the SEC filing.

Main Street Research LLC 13F Holdings -- Portfolio & Top Positions (2026-03-31)

Main Street Research LLC (CIK 1513211) reported $1.72B across 148 reported positions in its SEC 13F filing for 2026-03-31. Largest positions: NVDA ($108.3M, 6.30%), AAPL ($102.4M, 5.96%), GOOGL ($89.7M, 5.22%), ISCF ($81.9M, 4.76%), TSM ($75.4M, 4.39%). Source: SEC Form 13F.

RankTickerCompanyValue% PortfolioSharesAction
1NVDANVIDIA CORPORATION$108.3M6.30%620,776Added
2AAPLAPPLE INC$102.4M5.96%403,578Added
3GOOGLALPHABET INC$89.7M5.22%311,786Added
4ISCFISHARES TR$81.9M4.76%2.0MAdded
5TSMTAIWAN SEMICONDUCTOR MANUFAC$75.4M4.39%223,159Added
6XBISPDR SERIES TRUST$72.5M4.22%567,479Added
7JPMJPMORGAN CHASE & CO$65.8M3.83%223,762Added
8AVGOBROADCOM INC$65.7M3.83%212,402Added
9MCKMCKESSON CORP$58.6M3.41%67,774Added
10AMZNAMAZON COM INC$56.1M3.26%269,193Added
11ASMLASML HLDG NV$55.1M3.20%41,687Added
12GLWCORNING INC$52.7M3.07%387,718New
13COSTCOSTCO WHOLESALE CORPORATION$46.0M2.68%46,139Trimmed
14JNJJOHNSON & JOHNSON$45.7M2.66%186,882Added
15EWYISHARES INC$44.5M2.59%361,874Added
16GEVGE VERNOVA INC$44.2M2.57%50,692Added
17GLDMWORLD GOLD TR$43.5M2.53%469,451Added
18CATCATERPILLAR INC$43.3M2.52%61,110Added
19WMTWALMART INC$42.9M2.49%344,869Added
20CCJCAMECO CORP$42.3M2.46%389,077Added
21METAMETA PLATFORMS INC$40.6M2.36%70,962Trimmed
22APHAMPHENOL CORP$38.0M2.21%301,043Added
23BHPBHP BILLITON LIMITED$37.8M2.20%519,212New
24AZNCFASTRAZENECA PLC$37.6M2.19%190,644New
25MUMICRON TECHNOLOGY INC$36.9M2.14%109,109Added

Source: SEC Form 13F filings · as of 2026-03-31