ATI (ATI) Held by Superinvestors
ATI INC (ATI) is currently held by 4 superinvestors tracked by InsiderSet, with a combined reported market value of approximately $395.61M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Viking Global Investors is currently the largest disclosed institutional shareholder of ATI tracked by InsiderSet, reporting ownership valued at approximately $227.43M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $221.36M, representing an estimated loss of -2.67% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed ATI value among the investors covered in this analysis. Major shareholders include Viking Global Investors, Polen Capital Management, Sequoia Financial Advisors, and several other long-term asset managers with concentrated positions in ATI INC (ATI).
This page ranks the largest institutional ATI shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Viking Global Investors | Ole Andreas Halvorsen | 0.65% | 1,153,880 | $227,429,748 | $221,360,339 | -$6,069,409 | -2.67% |
| Polen Capital Management | David M. Polen | 1.39% | 819,236 | $161,471,378 | $157,162,234 | -$4,309,144 | -2.67% |
| Sequoia Financial Advisors | 0.03% | 33,554 | $6,613,494 | $6,436,999 | -$176,495 | -2.67% | |
| ARK Invest | Cathie Wood | 0.00% | 487 | $95,988 | $93,426 | -$2,562 | -2.67% |
Frequently asked questions about ATI
Who are the largest superinvestors holding ATI?
The largest superinvestors holding ATI in the latest SEC Form 13F filings include Viking Global Investors, Polen Capital Management, Sequoia Financial Advisors, and ARK Invest. InsiderSet ranks these superinvestors by their latest reported ATI position.
What does the ATI superinvestors page include?
This page tracks ATI positions reported by a curated group of notable institutional investors and fund managers through SEC Form 13F. ATI INC (ATI) on this page reflects disclosed 13F holdings among those superinvestors, not every institutional shareholder of the stock.
How many superinvestors hold ATI?
InsiderSet currently tracks 4 superinvestors reporting ATI holdings in the latest available 13F data. This is the curated set on this page, not the total number of institutions that own ATI.
How much ATI stock do superinvestors hold?
Superinvestors tracked by InsiderSet disclosed approximately $395.61M in ATI holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value, and it covers the curated superinvestors on this page rather than every institutional filer.
When were ATI superinvestor holdings last updated?
The latest ATI superinvestor holdings on InsiderSet are based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time holdings.
Are superinvestor ATI holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by these superinvestors as of the end of the reporting quarter. A superinvestor may have changed its ATI position after the reporting date.
Are superinvestors buying or selling ATI?
Buying and selling can be analyzed by comparing ATI positions across consecutive 13F reporting periods. InsiderSet's ATI Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View ATI ownership changes.
How have superinvestor ATI holdings changed over time?
InsiderSet tracks ATI holdings among these superinvestors across multiple 13F reporting periods, so holder counts, reported value, and reported shares can be compared over time.