American Tower Corp /ma/ vs Realty Income (AMT vs O)
Side by side from their SEC filings: revenue, margins, growth, returns and valuation, plus short interest, insider activity and institutional ownership.
American Tower Corp /ma/ is the larger company by revenue ($10.6B vs $5.7B) and market value ($78.5B vs $59.8B). Realty Income has grown revenue faster over the last 4 fiscal years (+176.4% cumulative vs +13.8%). American Tower Corp /ma/ trades at the lower trailing P/E (27.2x vs 52.6x).
About American Tower Corp /ma/
American Tower Corp is a global real estate investment trust that owns, operates, and develops multitenant communications real estate. The company leases space on its communications sites, including towers and distributed antenna system networks, to wireless service providers, broadcasters, government agencies, and other tenants. It also operates data centers and provides tower-related services such as site application, zoning, permitting, and construction management primarily in the United States.
About Realty Income
Realty Income Corporation is a real estate investment trust that acquires, owns, and manages freestanding commercial properties leased under long-term net lease agreements. The company serves a diversified base of clients, including investment grade and creditworthy operators, primarily in the United States, the United Kingdom, and Europe. Its portfolio includes retail properties and other commercial real estate types, and it focuses on generating stable rental income through properties important to its clients' operations.
Head to head (AMT FY2025 vs O FY2025)
| Metric | AMTFY2025 | OFY2025 |
|---|---|---|
| Revenue | $10.64B | $5.75B |
| Revenue growth (YoY) | 5.1% | 9.1% |
| Gross margin | — | — |
| Operating margin | 45.5% | — |
| Net margin | 24.7% | 18.4% |
| Net income | $2.63B | $1.06B |
| Diluted EPS | $5.40 | $1.17 |
| FCF margin | 35.5% | — |
| ROE | 25.4% | 2.6% |
| Debt / equity | 3.3× | — |
| Market cap | $78.54B | $59.84B |
| P/E (TTM) | 27.2× | 52.6× |
Fundamentals are from each company’s SEC filings (AMT FY2025, O FY2025). P/E and market cap are derived from recent market prices and update daily.
Five-year trend (as reported)
| Revenue | FY2021 | FY2022 | FY2023 | FY2024 | FY2025 |
|---|---|---|---|---|---|
| AMT | $9.36B | $9.65B | $10.01B | $10.13B | $10.64B |
| O | $2.08B | $3.34B | $4.08B | $5.27B | $5.75B |
Peer standing
Where each company ranks among the 165 REITs, on the same scale. Each figure is ranked only against peers that report it. Percentiles describe position in the distribution, not a rating.
| Metric | AMT | O |
|---|---|---|
| Net margin | 24.7%70th percentile of 156 | 18.4%63rd percentile of 156 |
| Revenue growth (YoY) | +5.1%59th percentile of 161 | +9.1%75th percentile of 161 |
| ROE | 25.4%96th percentile of 141 | 2.6%45th percentile of 141 |
| P/E (TTM) | 27.2×44th percentile of 108 | 52.6×80th percentile of 108 |
| Short interest (days to cover) | 1.92d21st percentile of 154 | 6.19d87th percentile of 154 |
Short interest
| FINRA settlement data | AMT | O |
|---|---|---|
| Shares sold short | 7.7M | 43.5M |
| Change vs prior settlement | -14.5% | +16.5% |
| Days to cover | 1.92 | 6.19 |
| As of settlement | 2026-06-30 | 2026-06-30 |
Source: FINRA Consolidated Short Interest. FINRA is the owner and source of the FINRA-supplied data; republishing or redistributing it is not permitted. Not presented as a percentage of float. No FINRA endorsement of this product is implied.
Insider activity (last 90 days)
| Form 4 open-market activity | AMT | O |
|---|---|---|
| Buys | 0 | — |
| Sells | 2 ($173,092) | — |
Open-market purchases and sales reported on SEC Form 4 (grants, exercises and tax withholding excluded). For context, about 16% of covered companies saw any open-market insider buy in a 90-day window.
Held by the same investors
7 tracked 13F managers hold both American Tower Corp /ma/ and Realty Income as of their latest quarterly filings: AQR Capital Management, Bridgewater Associates, Citadel Advisors, D. E. Shaw, Gotham Asset Management, Millennium Management, Two Sigma Investments. See which superinvestors hold your own portfolio with the smart money checker.
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Data sourced from SEC EDGAR (public domain). Figures are as-reported and may be unaudited or restated; verify against the source filings before relying on them. Comparisons are descriptive (higher or lower on a reported figure), not a rating or a recommendation. Informational only. Not investment advice.