13-F holdings, Q2 2026
Primecap Management Co
A 13-F is the report large US investment managers file with the SEC each quarter, listing the stocks they held at quarter end.
- Reported value
- $169.1B
- Positions
- 324
- Filed
- Data as of
These holdings are as of , 136 days ago.
13-Fs for Q3 2026 are due by .
See this manager's Holder IQ and how the book overlaps yours
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Top holdings
- MU$22.2B19,217,236 shares13.1% of the book
- LLY$11B9,172,904 shares6.5% of the book
- INTC$10.5B75,250,958 shares6.2% of the book
- KLAC$6.2B20,536,730 shares3.7% of the book
- GOOGL$5.3B14,859,769 shares3.1% of the book
- FLEX$3.8B23,358,875 shares2.2% of the book
- AZNCF$3.4B18,095,178 shares2% of the book
- NVDA$3.4B17,079,180 shares2% of the book
- BIIB$3.3B15,154,606 shares1.9% of the book
- AMZN$2.9B11,962,188 shares1.7% of the book
What changed this quarter
6 new positions and 6 sold out, against Q1 2026. Added and trimmed positions use the change in split-adjusted shares at the Q2 2026 implied price; full exits use their Q1 2026 reported value, not sale proceeds.
Largest buys
- BSX
BOSTON SCIENTIFIC CORP
+$767.9M
+55.3% shares
Your stake and evidence for BSX
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares increased between Q1 2026 and Q2 2026.
Displayed change: +$767.9M. The current book reports 50,520,914 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
50,520,914 current shares − 32,529,774 prior shares on the same basis = +17,991,140 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: 767861854.6587087 USD. Current reported shares: 50520914. Prior shares on current basis: 32529774.
- AAL
AMERICAN AIRLINES GROUP INC
+$392.9M
+44.4% shares
Your stake and evidence for AAL
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares increased between Q1 2026 and Q2 2026.
Displayed change: +$392.9M. The current book reports 70,732,954 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
70,732,954 current shares − 48,989,954 prior shares on the same basis = +21,743,000 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: 392896010.37502265 USD. Current reported shares: 70732954. Prior shares on current basis: 48989954.
- ILMN
ILLUMINA INC
+$254.5M
+70% shares
Your stake and evidence for ILMN
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares increased between Q1 2026 and Q2 2026.
Displayed change: +$254.5M. The current book reports 3,514,649 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
3,514,649 current shares − 2,067,299 prior shares on the same basis = +1,447,350 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: 254487551.04770064 USD. Current reported shares: 3514649. Prior shares on current basis: 2067299.
- MRSH
MARSH & MCLENNAN COS INC
+$237.9M
+199% shares
Your stake and evidence for MRSH
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares increased between Q1 2026 and Q2 2026.
Displayed change: +$237.9M. The current book reports 2,145,025 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
2,145,025 current shares − 717,500 prior shares on the same basis = +1,427,525 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: 237925592.58188134 USD. Current reported shares: 2145025. Prior shares on current basis: 717500.
- SCHW
SCHWAB CHARLES CORP
+$154.9M
+7.2% shares
Your stake and evidence for SCHW
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares increased between Q1 2026 and Q2 2026.
Displayed change: +$154.9M. The current book reports 25,120,895 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
25,120,895 current shares − 23,441,915 prior shares on the same basis = +1,678,980 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: 154919484.69022858 USD. Current reported shares: 25120895. Prior shares on current basis: 23441915.
Largest sells
- MU
MICRON TECHNOLOGY INC
−$3.1B
-12.1% shares
Your stake and evidence for MU
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares decreased between Q1 2026 and Q2 2026.
Displayed change: −$3.1B. The current book reports 19,217,236 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
19,217,236 current shares − 21,874,204 prior shares on the same basis = -2,656,968 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: -3066911592.659166 USD. Current reported shares: 19217236. Prior shares on current basis: 21874204.
- KLAC
KLA CORP
−$1.2B
-15.8% shares
Your stake and evidence for KLAC
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares decreased between Q1 2026 and Q2 2026.
Displayed change: −$1.2B. The current book reports 20,536,730 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
20,536,730 current shares − 24,376,470 prior shares on the same basis = -3,839,740 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: -1158487955.5308785 USD. Current reported shares: 20536730. Prior shares on current basis: 24376470.
- AMGN
AMGEN INC
−$766.7M
-23.9% shares
Your stake and evidence for AMGN
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares decreased between Q1 2026 and Q2 2026.
Displayed change: −$766.7M. The current book reports 6,756,962 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
6,756,962 current shares − 8,874,129 prior shares on the same basis = -2,117,167 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: -766668514.2154654 USD. Current reported shares: 6756962. Prior shares on current basis: 8874129.
- TXN
TEXAS INSTRS INC
−$339.7M
-11.8% shares
Your stake and evidence for TXN
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares decreased between Q1 2026 and Q2 2026.
Displayed change: −$339.7M. The current book reports 8,514,989 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
8,514,989 current shares − 9,654,766 prior shares on the same basis = -1,139,777 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: -339733330.35921323 USD. Current reported shares: 8514989. Prior shares on current basis: 9654766.
- FLEX
FLEXTRONICS INTL LTD
−$328.1M
-8% shares
Your stake and evidence for FLEX
What it means for you
This public view does not read your holdings or watchlist; open the member view to check your stake.
Use this to decide what to research, rather than as an instruction to copy a trade.
What happened
Reported shares decreased between Q1 2026 and Q2 2026.
Displayed change: −$328.1M. The current book reports 23,358,875 shares.
Why it can matter
A change between quarter-end disclosures can prompt a question about the manager's exposure. It does not reveal the trade date, the execution price or why the position changed; a full exit is not proof of a bearish decision.
How we got this
For an added or trimmed position, subtract split-adjusted prior shares from current shares, then multiply by the current book's reported value per share; this is not the execution price.
23,358,875 current shares − 25,383,448 prior shares on the same basis = -2,024,573 shares.
Comparable books exclude identified CUSIP, share-basis and new-security events from trades. Exit-size bands describe prior book weight, not the manager's intent.
Where the data comes from
SEC 13F quarter-end holdings for Q1 2026 and Q2 2026; these delayed disclosures omit shorts and many other assets.
Current source filed .
Technical details
Reported dollar change: -328122546.1750044 USD. Current reported shares: 23358875. Prior shares on current basis: 25383448.
What was sold out, by size
- 1 small, between 0.015% and 0.25%
- 5 slivers under 0.015%, often rounding or client flows
Not counted as trades: FDXF (newly listed or spun off), SPCX (newly listed or spun off), HONA (newly listed or spun off), FRVO (newly listed or spun off).
All of this comes from the filer's public SEC filings. A 13-F shows long positions in US-listed securities at quarter end and can leave out short positions, cash and non-US holdings, so it is not the whole portfolio. This is filing data, not investment advice.