Main Street Research portfolio
Type not verifiedPortfolio as of Jun 30, 2026 (Q2 2026) · filed with the SEC on Jul 29, 2026 · data updated on Nov 5, 2026 · Q2 2026 13F (filing) ↗ · all its 13F filings ↗
A 13F shows the portfolio at quarter-end and is filed up to 45 days later: these are not real-time positions and they may have changed.
Main Street Research reported a $2.1 bn portfolio of 138 companies (140 positions, counting each share class separately) to the SEC as of the end of Q2 2026. Its largest positions are NVDA, MU, GOOGL. During the quarter it opened Ross Stores and TechnipFMC and exited SPDR Gold Minishares Trust ETF.
Sections with a free account
What changed this quarter
134 positions with a change (13 new, 53 added to, 47 trimmed, 21 sold). 6 are listed here: those of 0.5 points of the portfolio or more (up to 12).
- SPDR Gold Minishares Trust ETF−2.1 ppof portfolioSold out2.5% → —
- Ross Stores+1.5 ppof portfolioNew— → 1.5%
- McKESSON−58%fewer sharesReduced3.4% → 1.0%
- TechnipFMC+1.3 ppof portfolioNew— → 1.3%
- Barclays+91%more sharesIncreased1.0% → 2.1%
- Palantir Technologies−93%fewer sharesReduced1.4% → 0.1%
The figure on the right: for positions added to or trimmed, the change in the number of shares (%); for new and sold ones, the points of the portfolio moved (pp). Below, the portfolio weight before → after. Traded weight: what it bought or sold, excluding price effects.
Top holdings
- NVIDIANVDA6.0%
- Micron TechnologyMU5.9%
- AlphabetGOOGL · GOOG5.7%
- AppleAAPL5.5%
- Taiwan Semiconductor ManufacturingTSM5.1%
- CorningGLW4.8%
- State Street SPDR S&P Biotech ETFXBI4.3%
- iShares International Small ETFISCF4.1%
- ASML HoldingASML4.0%
- BroadcomAVGO3.8%
- JPMorgan ChaseJPM3.5%
- IsharesEWY3.4%
- CaterpillarCAT3.1%
- Amazon.comAMZN3.1%
- GE VernovaGEV2.8%
“Since”: first quarter of the current run, unbroken until today. In the details, prices are the quarter-end prices of the quarters in which it added shares, per the 13F. The manager may have bought at any price within each quarter; the SEC only publishes the value at quarter end.
Portfolio by sector
- ● Information Technology 43%
- ● No sector 13%
- ● Financials 9%
- ● Communication Services 8%
- ● Industrials 6%
- ● Health Care 5%
- ● Consumer Staples 5%
- ● Consumer Discretionary 5%
- ● Energy 3%
- ● Materials 2%
How its portfolio changed (8 quarters)
Q2 2026: 140
Q2 2026: 49%
Q2 2026: 5.4%
Traded turnover: the weight it bought plus the weight it sold in the quarter, divided by two, excluding price moves. The plain “turnover” in the header does include that effect. With a free account: the full history and sectors over time.
Stakes above 5% (13D/13G)
Companies where this filer reported holding 5% or more of the shares. It is the figure from its latest filing on each one; history since December 2024.
How we classify it
Type not verified: we have not assigned a type because we found no document that is enough to tell. Most 13F filers are in this situation: we only review in depth those that meet the portfolio criteria.
Not counted as a concentrated manager: its portfolio is not within 5 to 100 positions. Its portfolio is shown all the same, but it is left out of manager counts, the consensus and the ranking. How this is decided
Managers of a similar size
A 13F portfolio value between a third and three times this one, whatever the type of filer. It is not a comparison of what they hold.
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