Investigate / reported ownership
COST
Costco Wholesale Corp
8 tracked reported owners · snapshot updated 2026-10-04. Delayed disclosures, not live holdings or an investment recommendation.
Who reports owning COST?
Select a manager to inspect their portfolio. Reports may cover different quarters; portfolio weights describe disclosed long 13F holdings, not total economic exposure.
| #↑ | Manager | % Port. | History | Value | Shares |
|---|---|---|---|---|---|
| 1 | Joel Greenblatt | 0.3% | 39q | $477M | 509,661 |
| 2 | Thomas Gayner | 0.3% | 40q | $37M | 39,150 |
| 3 | Thomas Russo | <0.1% | 40q | $3M | 3,399 |
| 4 | Christopher Bloomstran | 0.4% | 40q | $3M | 3,354 |
| 5 | Mairs & Power Funds | <0.1% | 40q | $3M | 2,963 |
Go beyond ownership.
Costco operates membership warehouses and e-commerce sites selling a limited selection of branded and private-label goods at low prices, aiming for high volumes and rapid inventory turnover.
Question to investigate: Can Costco keep growing comparable sales while its profits remain concentrated in U.S. and Canadian operations?
Company research reviewed 2026-10-02; a dated source-linked starting point, not the investors’ stated reasons.
Understand the business and investment case →Filing dates and original SEC sources
- Joel Greenblatt · 2026Q2 · filed 2026-09-02 ↗
- Thomas Gayner · 2026Q2 · filed 2026-07-31 ↗
- Thomas Russo · 2026Q2 · filed 2026-08-13 ↗
- Christopher Bloomstran · 2026Q2 · filed 2026-08-14 ↗
- Mairs & Power Funds · 2026Q2 · filed 2026-08-14 ↗
- Torray Funds · 2026Q2 · filed 2026-07-30 ↗
- David Katz · 2026Q2 · filed 2026-07-15 ↗
- Bill Nygren · 2026Q2 · filed 2026-08-14 ↗
Reported position changes
Net disclosed share changes—not individual trades or execution dates. NEW has no prior-position percentage comparison; EXIT weight refers to the previous report.
| Manager | Move | % Port. | Δ Shares | Value | Filed |
|---|---|---|---|---|---|
| Thomas Russo | TRIM | <0.1% | -26% | $3M | Aug 13, 2026 |
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Long US 13F disclosures omit shorts and can be amended. CUSIP 22160K105. No current price, valuation or manager motive is inferred.