Exited position

Warren Buffett’s Costco (COST) position

Reported position history, portfolio importance and verified filing changes from public SEC disclosures.

Berkshire HathawayVerified through Q2 2026
Relationship snapshot

At a glance

The full verified relationship, including prior ownership episodes and exits where supported.

First reportedQ2 2002Earliest verified positive filing snapshot
Latest statusExited positionBased on the latest supported relationship state
Peak shares5.61MHighest verified quarter-end share count
Quarters reported69Verified quarters with shares above zero
What happened?

Berkshire Hathaway first reported Costco in Q2 2002. The reported position was reduced across later filings. The latest verified relationship event shows that Berkshire Hathaway sold the entire position in Q3 2020, and the stock is no longer reported in the latest verified portfolio.

Verified SEC history

Position over time

See the same verified relationship through reported shares, portfolio weight or reported value.

Metric

Gaps indicate periods that cannot be safely connected or where a verified corporate action changes the raw share scale. Stock price, when available, is market context and not a transaction price.

Key filing events

What changed

Latest filing plus the most meaningful reported changes. Unchanged quarters are collapsed by default.

Q3 2020
Sold the entire position−4.33M shares · No shares reported at quarter-end
Q1 2010
Sold 17.5% of the position−920.64K shares · 4.33M shares remained
Filing context

Quarter-end price $59.71 · Estimated holding basis $53.84

Q4 2002
Sold 6.3% of the position−352.41K shares · 5.25M shares remained
Filing context

Quarter-end price $28.06 · Estimated holding basis $38.57

Q2 2002
New position+5.61M shares · 5.61M shares reported
Filing context

Quarter-end price $38.57 · Estimated holding basis $38.57

62 unchanged quarters are collapsed by default.

Portfolio importance

How important was Costco in Berkshire Hathaway’s reported portfolio?

Relative importance is measured only within the verified primary non-option reported portfolio for each quarter.

Last reported portfolio weight0.6%Q2 2020
Last reported rank#19of 44 reported positions
Peak portfolio weight0.7%Q4 2004
Best historical rank#14Q4 2010
At peak importanceQ4 2004
COST
0.7%
Largest holding
23.9%
Cross-investor discovery

Who else owns Costco?

Also reported by 4 other tracked investors in their latest verified filings.

Christopher BloomstranSemper Augustus Investments Group LLC
COST0.4% of reported portfolio
Ray DalioBridgewater Associates, LP
COST0.1% of reported portfolio
Joel GreenblattGotham Asset Management
COST0.1% of reported portfolio
Explore Costco across all tracked investors →
SEC evidence & methodology

SEC filing evidence

Market context and filing-derived values are kept separate from actual transaction prices, which 13F filings do not disclose.

Latest verified stock price$904.772026-09-11

Market context only; not an investor transaction price.

Latest verified investor filingQ2 2026 · filed 2026-08-14
Open SEC filing ↗

View Costco stock page →

This tracker follows Berkshire Hathaway’s Form 13F disclosures. It is not Warren Buffett’s personal brokerage account, and 13F filings do not reveal exact trade dates or execution prices.