American Tower (AMT) Market Cap 1998–2025

As of December 12, 2025, American Tower had a market cap of $84.550 billion, which decreased by 0.61% compared to the previous trading day. Market capitalization, often referred to as market cap, represents the total value of a company's outstanding shares on the stock market and is a common measure of its overall size and valuation.

Data updated: Dec 12, 2025, 4:00 PM ET
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American Tower Corp. (AMT)

🌍 United States 📈 NYSE 🏭 Real Estate 🏢 Specialized REITs
Latest Market Cap
$84.550B ▼ 0.61%
Jan 1, 2025
$85.722B ▼ 1.37%
1 Year Ago
$92.131B ▼ 8.23%
All-Time High
$138.190B ▼ 38.82%


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Note: Each point on the chart represents the market capitalization at the end of the trading day.
Source: Data compiled from EDGAR filings, Bloomberg and Yahoo Finance.


📈 American Tower Market Cap History by Year and Month

American Tower Market Cap History by Year and Month
Year / MonthMarket Cap% Change
2025$84.550B▼ 1.37%
$84.550B▼ 0.37%
$84.860B▲ 1.28%
$83.790B▼ 6.95%
$90.050B▼ 5.66%
$95.450B▼ 2.18%
$97.580B▼ 5.69%
$103.470B▲ 2.97%
$100.490B▼ 4.77%
$105.520B▲ 3.59%
$101.860B▲ 5.97%
$96.120B▲ 11.20%
$86.440B▲ 0.84%
2024$85.722B▼ 14.82%
2023$100.637B▲ 2.02%
2022$98.644B▼ 26.01%
2021$133.313B▲ 33.67%

All market cap values reflect closing prices for the period shown.


📊 American Tower Market Cap and Other Industry Peers

Below are selected companies from the Real Estate sector / subsector:

  1. $128.16B
  2. $120.91B
  3. $84.55B
  4. $73.68B
  5. $59.42B
  6. $53.09B
  7. $52.80B
  8. $48.25B
  9. $47.48B
  10. $39.62B
  11. $30.64B
  12. $28.54B
  13. $24.64B
  14. $20.43B
  15. $16.88B
  16. $12.96B
  17. $12.30B
  18. $8.33B
  19. $5.26B
  20. $3.81B

Data reflect the most recent market capitalization values available.

💡 What Is Market Capitalization and How Do We Calculate It?

For American Tower Corp. (AMT), market capitalization represents the total market value of the company’s publicly traded shares. It helps investors understand American Tower’s size within the real estate sector and compare it with other companies in the same industry.

In most cases, market capitalization is calculated by multiplying the current share price by the number of basic shares outstanding. Basic shares represent the actual number of common shares that currently exist, without including potential future shares from employee stock options, RSUs, warrants, or convertible securities. For example, if American Tower had one million basic shares and each traded at $50, its market capitalization would be $50 million.

Formula:
Market Cap = Share Price × Shares Outstanding

The value of American Tower’s market capitalization changes throughout the trading day because it mainly depends on the current share price. The number of shares outstanding typically remains stable unless the company issues new shares, buys back its own stock, or grants stock options to employees.

Based on the latest data, American Tower had a market capitalization of $84.550 billion, placing it in the large-cap category within the real estate industry.

Disclaimer: Despite all efforts, there may still be minor inaccuracies present in the data.