American Tower Corp (AMT) is slightly overvalued and Iron Mountain Inc (IRM) is overvalued.
Both trade above our estimate of their intrinsic value. AMT is the closer of the two: -16%, against -208% for IRM.
Values as of the 22 Sept 2026 close.
Discounting its cash flows at 8.7% (average of 3 methods) values the shares at $151.19; the price of $175.25 is 16% above that value, and 77% of that value comes from beyond year five.
Leak Score 45/100 on 9 of 12 signals
Discounting its cash flows at 8.9% (average of 2 methods) values the shares at $38.38; the price of $118.13 is 208% above that value.
Leak Score 28/100 on 8 of 12 signals
| Metric | AMT | IRM |
|---|---|---|
| Verdict | Slightly overvalued | Overvalued |
| Price | $175.25 | $118.13 |
| Intrinsic value | $151.19 | $38.38 |
| Margin of safety | -16% | -208% |
| Leak Score | 45/100 (9/12) | 28/100 (8/12) |
| Market cap | $81.7B | $35.2B |
| Revenue growth, 5 years | 5.8% | 10.7% |
| Operating margin | 45.2% | 20.6% |
| Net margin | 31.1% | 5.5% |
| Return on equity | 91.5% | — |
| Debt to equity | 12.09 | — |
| P/E | 24.1x | 84.3x |
| Forward P/E | 24.9x | 42.5x |
| P/B | 21.9x | — |
| Dividend yield | 4.1% | 2.9% |