AMERICAN TOWER CORP (AMT) Top Institutional Shareholders
AMERICAN TOWER CORP (AMT) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended March 31, 2026. The institutional investors covered on this page collectively reported approximately $289.63M in AMT holdings during the latest filing period.
Cantillon Capital Management is currently the largest disclosed institutional shareholder of AMT tracked by InsiderSet, reporting ownership valued at approximately $278.28M in its March 31, 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 $289.25M, representing an estimated gain of +3.94% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed AMT value among the investors covered in this analysis. Major shareholders include Cantillon Capital Management, Akre Capital Management, Sequoia Financial Advisors, and several other long-term asset managers with concentrated positions in AMERICAN TOWER CORP (AMT).
This page ranks the largest institutional AMT 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 |
|---|---|---|---|---|---|---|---|
| Cantillon Capital Management | William Von Mueffling | 1.85% | 1,612,473 | $278,280,591 | $289,245,407 | +$10,964,816 | +3.94% |
| Akre Capital Management | Chuck Akre | 0.14% | 50,772 | $8,762,232 | $9,107,481 | +$345,249 | +3.94% |
| Sequoia Financial Advisors | 0.01% | 9,105 | $1,571,293 | $1,633,255 | +$61,962 | +3.94% | |
| Alapocas Investment Partners | David Lemons | 0.51% | 3,876 | $668,920 | $695,277 | +$26,357 | +3.94% |
| Mairs & Power Growth Fund | Andrew R. Adams | 0.00% | 2,020 | $348,612 | $362,348 | +$13,736 | +3.94% |
Frequently asked questions about AMT
Who owns the most AMT stock?
The largest holders of AMT are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for AMERICAN TOWER CORP (AMT).
Is AMT widely held by superinvestors?
Many widely followed stocks like AMT appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly AMT is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.