Main Street Research LLC

Q3 2025 13F-HR Holdings

Location
Sausalito, CA
Holdings as of
9/30/2025
Date filed
11/13/2025
Form type
13F-HR
Num holdings
129
Total value ($000)
$1,850,823
Net value change ($000)
+244,329 (15.2%)
New positions
20
Sold out positions
6
Turnover %
18.4%
Sector allocation + QoQ delta (equities-only)
Prev filing: 8/5/2025 Next filing: 2/9/2026 SEC filing

Snapshot: Change Analysis

Compared to Q2 2025
Methodology: sector metrics are equities-only; instrument mix chart is ex-options; options exposure is shown separately. Why this matters.
Top Adds (Value $000, Stocks/ETFs)
ISCF 61,482 NEW
MSFT 39,995 84.9%
APH 36,792 NEW
BCS 35,035 NEW
CCJ 30,558 NEW
TSM 30,557 98.2%
AAPL 29,054 48.1%
APO 28,929 NEW
HOOD 26,963 53.7%
ASML 25,122 179.2%
Top Reduces (Value $000, Stocks/ETFs)
BRK-B -49,770 -88.2%
PG -41,359 -63.8%
BSX -40,326 -98.5%
SAP -36,712 -100.0%
ISRG -32,340 -100.0%
CHKP -30,258 -100.0%
BABA -26,078 -100.0%
FICO -6,692 -34.1%
NFLX -5,574 -9.8%
MELI -4,106 -10.0%
Instrument mix + QoQ Δ (ex-options)
How this table is calculated: SEC VALUE ($000) is used as reported. For derivatives (PUT/CALL/WARRANT/RIGHT), SEC value represents reported underlying exposure, not premium cash paid/received. Column % is bucket-based: non-options share is calculated inside non-option total, options share is calculated inside options total. Details.
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Instrument:
Issuer Name Ticker Sector Industry Class History Value ($000) % Shares Shares Δ Shares Δ% Value Δ ($000) Value Δ% Principal Option Type