American Tower (AMT) Market Cap 1998–2026

As of October 29, 2026, American Tower had a market cap of $86.28 billion, which increased by 0.77% 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: Oct 29, 2026, 4:00 PM ET

American Tower Corp. (AMT)

🌍 United States 📈 NYSE 🏭 Real Estate 🏢 Specialized REITs

Latest Market Cap

$86.28B ▲ 0.77%

Start of 2026

$82.19B ▲ 4.98%

1 Year Ago

$84.01B ▲ 2.70%

All-Time High

$138.19B ▼ 37.56%

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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 / Month	Market Cap	% Change
2026	$86.28B	▲ 4.98%
October 29, 2026	$86.28B	▲ 13.12%
September 30, 2026	$76.27B	▼ 6.84%
August 31, 2026	$81.87B	▲ 1.35%
July 31, 2026	$80.78B	▲ 5.98%
June 30, 2026	$76.22B	▼ 12.49%
May 29, 2026	$87.1B	▲ 2.33%
April 30, 2026	$85.12B	▲ 5.82%
March 31, 2026	$80.44B	▼ 10.44%
February 27, 2026	$89.82B	▲ 7.02%
January 30, 2026	$83.93B	▲ 2.12%
2025	$82.19B	▼ 4.12%
December 31, 2025	$82.19B	▼ 3.15%
November 28, 2025	$84.86B	▲ 1.28%
October 31, 2025	$83.79B	▼ 6.95%
September 30, 2025	$90.05B	▼ 5.66%
August 29, 2025	$95.45B	▼ 2.18%
July 31, 2025	$97.58B	▼ 5.69%
June 30, 2025	$103.47B	▲ 2.97%
May 30, 2025	$100.49B	▼ 4.77%
April 30, 2025	$105.52B	▲ 3.59%
March 31, 2025	$101.86B	▲ 5.97%
February 28, 2025	$96.12B	▲ 11.20%
January 31, 2025	$86.44B	▲ 0.84%
2024	$85.722B	▼ 14.82%
December 31, 2024	$85.722B	▼ 12.23%
November 29, 2024	$97.664B	▼ 2.13%
October 31, 2024	$99.785B	▼ 8.18%
September 30, 2024	$108.671B	▲ 3.84%
August 30, 2024	$104.654B	▲ 1.66%
July 31, 2024	$102.944B	▲ 13.41%
June 28, 2024	$90.772B	▼ 0.69%
May 31, 2024	$91.407B	▲ 14.09%
April 30, 2024	$80.115B	▼ 13.17%
March 28, 2024	$92.267B	▼ 0.51%
February 29, 2024	$92.738B	▲ 1.65%
January 31, 2024	$91.232B	▼ 9.35%
2023	$100.637B	▲ 2.02%
December 29, 2023	$100.637B	▲ 3.40%
November 30, 2023	$97.327B	▲ 17.17%
October 31, 2023	$83.067B	▲ 8.36%
September 29, 2023	$76.66B	▼ 9.30%
August 31, 2023	$84.524B	▼ 4.72%
July 31, 2023	$88.715B	▼ 1.87%
June 30, 2023	$90.401B	▲ 5.17%
May 31, 2023	$85.956B	▼ 9.76%
April 28, 2023	$95.254B	▲ 0.02%
March 31, 2023	$95.231B	▲ 3.28%
February 28, 2023	$92.203B	▼ 11.36%
January 31, 2023	$104.015B	▲ 5.44%
2022	$98.644B	▼ 26.01%
December 30, 2022	$98.644B	▼ 4.24%
November 30, 2022	$103.016B	▲ 6.79%
October 31, 2022	$96.47B	▼ 3.50%
September 30, 2022	$99.964B	▼ 15.49%
August 31, 2022	$118.283B	▼ 6.20%
July 29, 2022	$126.096B	▲ 5.96%
June 30, 2022	$118.998B	▲ 1.81%
May 31, 2022	$116.885B	▲ 6.29%
April 29, 2022	$109.973B	▼ 4.06%
March 31, 2022	$114.627B	▲ 10.83%
February 28, 2022	$103.425B	▼ 9.77%
January 31, 2022	$114.626B	▼ 14.02%
2021	$133.313B	▲ 33.67%
December 31, 2021	$133.313B	▲ 11.53%
November 30, 2021	$119.536B	▼ 6.91%
October 29, 2021	$128.412B	▲ 6.24%
September 30, 2021	$120.87B	▼ 9.11%
August 31, 2021	$132.978B	▲ 3.31%
July 30, 2021	$128.714B	▲ 4.71%
June 30, 2021	$122.922B	▲ 5.82%
May 28, 2021	$116.158B	▲ 2.50%
April 30, 2021	$113.322B	▲ 6.57%
March 31, 2021	$106.331B	▲ 10.71%
February 26, 2021	$96.044B	▼ 4.93%
January 29, 2021	$101.023B	▲ 1.29%
2020	$99.734B	▼ 2.02%
December 31, 2020	$99.734B	▼ 2.89%
November 30, 2020	$102.701B	▲ 0.67%
October 30, 2020	$102.013B	▼ 4.99%
September 30, 2020	$107.374B	▼ 2.84%
August 31, 2020	$110.515B	▼ 4.68%
July 31, 2020	$115.945B	▲ 1.10%
June 30, 2020	$114.678B	▲ 0.20%
May 29, 2020	$114.449B	▲ 8.47%
April 30, 2020	$105.508B	▲ 9.30%
March 31, 2020	$96.535B	▼ 3.90%
February 28, 2020	$100.452B	▼ 2.13%
January 31, 2020	$102.635B	▲ 0.84%
2019	$101.785B	▲ 45.88%
December 31, 2019	$101.785B	▲ 7.37%
November 29, 2019	$94.802B	▼ 1.86%
October 31, 2019	$96.596B	▼ 1.36%
September 30, 2019	$97.925B	▼ 3.90%
August 30, 2019	$101.903B	▲ 8.78%
July 31, 2019	$93.682B	▲ 3.66%
June 28, 2019	$90.371B	▼ 2.07%
May 31, 2019	$92.281B	▲ 6.90%
April 30, 2019	$86.327B	▼ 0.88%
March 29, 2019	$87.095B	▲ 12.08%
February 28, 2019	$77.705B	▲ 1.93%
January 31, 2019	$76.233B	▲ 9.26%
2018	$69.771B	▲ 15.62%
December 31, 2018	$69.771B	▼ 3.71%
November 30, 2018	$72.456B	▲ 5.57%
October 31, 2018	$68.633B	▲ 7.15%
September 28, 2018	$64.054B	▼ 2.56%
August 31, 2018	$65.738B	▲ 0.59%
July 31, 2018	$65.35B	▲ 2.63%
June 29, 2018	$63.674B	▲ 4.19%
May 31, 2018	$61.112B	▲ 1.47%
April 30, 2018	$60.225B	▼ 6.16%
March 29, 2018	$64.181B	▲ 4.49%
February 28, 2018	$61.424B	▼ 3.02%
January 31, 2018	$63.337B	▲ 4.96%
2017	$60.344B	▲ 33.75%
December 29, 2017	$60.344B	▼ 0.88%
November 30, 2017	$60.877B	▲ 0.18%
October 31, 2017	$60.767B	▲ 3.59%
September 29, 2017	$58.66B	▼ 7.68%
August 31, 2017	$63.54B	▲ 8.60%
July 31, 2017	$58.51B	▲ 3.03%
June 30, 2017	$56.789B	▲ 1.85%
May 31, 2017	$55.757B	▲ 4.17%
April 28, 2017	$53.526B	▲ 3.32%
March 31, 2017	$51.806B	▲ 5.64%
February 28, 2017	$49.038B	▲ 10.91%
January 31, 2017	$44.215B	▼ 2.00%
2016	$45.116B	▲ 9.78%
December 30, 2016	$45.116B	▲ 3.62%
November 30, 2016	$43.54B	▼ 12.72%
October 31, 2016	$49.887B	▲ 3.42%
September 30, 2016	$48.236B	▼ 0.01%
August 31, 2016	$48.242B	▼ 2.06%
July 29, 2016	$49.259B	▲ 1.96%
June 30, 2016	$48.314B	▲ 7.57%
May 31, 2016	$44.916B	▲ 0.86%
April 29, 2016	$44.534B	▲ 2.47%
March 31, 2016	$43.462B	▲ 11.20%
February 29, 2016	$39.084B	▼ 2.27%
January 29, 2016	$39.99B	▼ 2.69%
2015	$41.096B	▲ 4.80%
December 31, 2015	$41.096B	▼ 2.37%
November 30, 2015	$42.094B	▼ 2.79%
October 30, 2015	$43.302B	▲ 16.22%
September 30, 2015	$37.26B	▼ 4.52%
August 31, 2015	$39.022B	▼ 3.07%
July 31, 2015	$40.258B	▲ 1.96%
June 30, 2015	$39.486B	▲ 0.58%
May 29, 2015	$39.259B	▼ 1.84%
April 30, 2015	$39.995B	▲ 0.41%
March 31, 2015	$39.832B	▲ 1.28%
February 27, 2015	$39.33B	▲ 2.26%
January 30, 2015	$38.46B	▼ 1.92%
2014	$39.214B	▲ 24.42%
December 31, 2014	$39.214B	▼ 5.81%
November 28, 2014	$41.632B	▲ 7.70%
October 31, 2014	$38.655B	▲ 4.15%
September 30, 2014	$37.115B	▼ 4.98%
August 29, 2014	$39.059B	▲ 4.46%
July 31, 2014	$37.392B	▲ 4.94%
June 30, 2014	$35.632B	▲ 0.45%
May 30, 2014	$35.471B	▲ 7.32%
April 30, 2014	$33.053B	▲ 2.04%
March 31, 2014	$32.393B	▲ 0.66%
February 28, 2014	$32.182B	▲ 0.77%
January 31, 2014	$31.936B	▲ 1.33%
2013	$31.518B	▲ 3.24%
December 31, 2013	$31.518B	▲ 2.69%
November 29, 2013	$30.691B	▼ 1.99%
October 31, 2013	$31.315B	▲ 7.07%
September 30, 2013	$29.247B	▲ 6.55%
August 30, 2013	$27.449B	▼ 1.83%
July 31, 2013	$27.962B	▼ 3.37%
June 28, 2013	$28.938B	▼ 6.00%
May 31, 2013	$30.785B	▼ 7.32%
April 30, 2013	$33.217B	▲ 9.16%
March 28, 2013	$30.43B	▼ 0.75%
February 28, 2013	$30.66B	▲ 1.91%
January 31, 2013	$30.086B	▼ 1.45%
2012	$30.529B	▲ 29.44%
December 31, 2012	$30.529B	▲ 3.05%
November 30, 2012	$29.624B	▼ 0.48%
October 31, 2012	$29.766B	▲ 5.52%
September 28, 2012	$28.21B	▲ 1.41%
August 31, 2012	$27.819B	▼ 2.64%
July 31, 2012	$28.574B	▲ 3.58%
June 29, 2012	$27.586B	▲ 7.75%
May 31, 2012	$25.601B	▼ 1.07%
April 30, 2012	$25.877B	▲ 4.29%
March 30, 2012	$24.812B	▲ 0.70%
February 29, 2012	$24.639B	▼ 1.44%
January 31, 2012	$25B	▲ 6.00%
2011	$23.586B	▲ 14.56%
December 30, 2011	$23.586B	▲ 1.71%
November 30, 2011	$23.189B	▲ 7.08%
October 31, 2011	$21.656B	▲ 2.30%
September 30, 2011	$21.169B	▼ 0.69%
August 31, 2011	$21.316B	▲ 2.53%
July 29, 2011	$20.789B	▲ 0.32%
June 30, 2011	$20.723B	▼ 5.83%
May 31, 2011	$22.005B	▲ 6.06%
April 29, 2011	$20.748B	▲ 0.84%
March 31, 2011	$20.576B	▼ 4.10%
February 28, 2011	$21.455B	▲ 5.81%
January 31, 2011	$20.277B	▼ 1.51%
2010	$20.588B	▲ 18.64%
December 31, 2010	$20.588B	▲ 2.02%
November 30, 2010	$20.181B	▼ 2.02%
October 29, 2010	$20.597B	▲ 0.55%
September 30, 2010	$20.484B	▲ 8.97%
August 31, 2010	$18.797B	▲ 1.34%
July 30, 2010	$18.549B	▲ 3.75%
June 30, 2010	$17.878B	▲ 9.34%
May 28, 2010	$16.351B	▼ 0.69%
April 30, 2010	$16.464B	▼ 4.28%
March 31, 2010	$17.201B	▲ 0.13%
February 26, 2010	$17.178B	▲ 0.76%
January 29, 2010	$17.048B	▼ 1.76%
2009	$17.353B	▲ 49.20%
December 31, 2009	$17.353B	▲ 5.64%
November 30, 2009	$16.427B	▲ 11.14%
October 30, 2009	$14.781B	▲ 1.25%
September 30, 2009	$14.599B	▲ 16.89%
August 31, 2009	$12.49B	▼ 7.16%
July 31, 2009	$13.453B	▲ 7.80%
June 30, 2009	$12.48B	▼ 1.53%
May 29, 2009	$12.674B	▲ 0.34%
April 30, 2009	$12.631B	▲ 4.53%
March 31, 2009	$12.084B	▲ 4.50%
February 27, 2009	$11.564B	▼ 3.92%
January 30, 2009	$12.036B	▲ 3.48%
2008	$11.631B	▼ 31.66%
December 31, 2008	$11.631B	▲ 7.63%
November 28, 2008	$10.806B	▼ 15.69%
October 31, 2008	$12.817B	▼ 9.55%
September 30, 2008	$14.17B	▼ 12.97%
August 29, 2008	$16.282B	▼ 1.36%
July 31, 2008	$16.506B	▼ 1.39%
June 30, 2008	$16.739B	▼ 7.68%
May 30, 2008	$18.131B	▲ 5.30%
April 30, 2008	$17.219B	▲ 10.89%
March 31, 2008	$15.528B	▲ 2.07%
February 29, 2008	$15.213B	▲ 1.73%
January 31, 2008	$14.954B	▼ 12.14%
2007	$17.02B	▲ 7.30%
December 31, 2007	$17.02B	▼ 7.66%
November 30, 2007	$18.432B	▲ 3.08%
October 31, 2007	$17.881B	▼ 0.03%
September 28, 2007	$17.887B	▲ 9.89%
August 31, 2007	$16.277B	▼ 4.90%
July 31, 2007	$17.115B	▼ 2.92%
June 29, 2007	$17.63B	▼ 2.73%
May 31, 2007	$18.125B	▲ 13.63%
April 30, 2007	$15.951B	▼ 2.49%
March 30, 2007	$16.359B	▲ 0.60%
February 28, 2007	$16.262B	▼ 2.29%
January 31, 2007	$16.643B	▲ 4.92%
2006	$15.862B	▲ 42.13%
December 29, 2006	$15.862B	▼ 1.56%
November 30, 2006	$16.113B	▲ 5.14%
October 31, 2006	$15.326B	▼ 1.21%
September 29, 2006	$15.514B	▲ 1.78%
August 31, 2006	$15.242B	▲ 6.10%
July 31, 2006	$14.366B	▲ 8.61%
June 30, 2006	$13.227B	▲ 1.79%
May 31, 2006	$12.995B	▼ 9.44%
April 28, 2006	$14.35B	▲ 12.60%
March 31, 2006	$12.744B	▼ 2.98%
February 28, 2006	$13.135B	▲ 2.88%
January 31, 2006	$12.767B	▲ 14.40%
2005	$11.16B	▲ 164.14%
December 30, 2005	$11.16B	▼ 0.70%
November 30, 2005	$11.239B	▲ 14.43%
October 31, 2005	$9.822B	▼ 4.18%
September 30, 2005	$10.251B	▲ 85.77%
August 31, 2005	$5.518B	▲ 3.90%
July 29, 2005	$5.311B	▲ 9.32%
June 30, 2005	$4.858B	▲ 16.75%
May 31, 2005	$4.161B	▲ 4.71%
April 29, 2005	$3.974B	▼ 5.47%
March 31, 2005	$4.204B	▼ 0.12%
February 28, 2005	$4.209B	▲ 1.18%
January 31, 2005	$4.16B	▼ 1.54%
2004	$4.225B	▲ 77.60%
December 31, 2004	$4.225B	▲ 2.08%
November 30, 2004	$4.139B	▲ 7.28%
October 29, 2004	$3.858B	▲ 11.99%
September 30, 2004	$3.445B	▲ 3.08%
August 31, 2004	$3.342B	▲ 3.12%
July 30, 2004	$3.241B	▼ 4.87%
June 30, 2004	$3.407B	▲ 10.26%
May 28, 2004	$3.09B	▲ 12.24%
April 30, 2004	$2.753B	▲ 9.72%
March 31, 2004	$2.509B	▲ 3.25%
February 27, 2004	$2.43B	▲ 0.54%
January 30, 2004	$2.417B	▲ 1.60%
2003	$2.379B	▲ 244.28%
December 31, 2003	$2.379B	▼ 4.76%
November 28, 2003	$2.498B	▼ 1.85%
October 31, 2003	$2.545B	▲ 14.28%
September 30, 2003	$2.227B	▼ 10.60%
August 29, 2003	$2.491B	▲ 33.78%
July 31, 2003	$1.862B	▲ 2.87%
June 30, 2003	$1.81B	▼ 0.44%
May 30, 2003	$1.818B	▲ 39.52%
April 30, 2003	$1.303B	▲ 20.20%
March 31, 2003	$1.084B	▲ 18.08%
February 28, 2003	$0.918B	▼ 7.65%
January 31, 2003	$0.994B	▲ 43.85%
2002	$0.691B	▼ 62.63%
December 31, 2002	$0.691B	▼ 9.20%
November 29, 2002	$0.761B	▲ 175.72%
October 31, 2002	$0.276B	▼ 11.25%
September 30, 2002	$0.311B	▼ 35.34%
August 30, 2002	$0.481B	▲ 9.82%
July 31, 2002	$0.438B	▼ 35.01%
June 28, 2002	$0.674B	▼ 9.16%
May 31, 2002	$0.742B	▼ 23.82%
April 30, 2002	$0.974B	▼ 9.31%
March 28, 2002	$1.074B	▲ 13.65%
February 28, 2002	$0.945B	▼ 6.25%
January 31, 2002	$1.008B	▼ 45.48%
2001	$1.849B	▼ 72.72%
December 31, 2001	$1.849B	▲ 7.69%
November 30, 2001	$1.717B	▼ 20.14%
October 31, 2001	$2.15B	▼ 19.02%
September 28, 2001	$2.655B	▼ 4.01%
August 31, 2001	$2.766B	▼ 14.60%
July 31, 2001	$3.239B	▼ 17.83%
June 29, 2001	$3.942B	▼ 16.45%
May 31, 2001	$4.718B	▼ 7.74%
April 30, 2001	$5.114B	▲ 45.12%
March 30, 2001	$3.524B	▼ 36.08%
February 28, 2001	$5.513B	▼ 15.65%
January 31, 2001	$6.536B	▼ 3.56%
2000	$6.777B	▲ 42.34%
December 29, 2000	$6.777B	▲ 25.73%
November 30, 2000	$5.39B	▼ 26.07%
October 31, 2000	$7.291B	▲ 8.18%
September 29, 2000	$6.74B	▲ 3.61%
August 31, 2000	$6.505B	▼ 14.74%
July 31, 2000	$7.63B	▲ 2.84%
June 30, 2000	$7.419B	▲ 26.24%
May 31, 2000	$5.877B	▼ 19.89%
April 28, 2000	$7.336B	▼ 5.69%
March 31, 2000	$7.779B	▲ 1.39%
February 29, 2000	$7.672B	▲ 37.27%
January 31, 2000	$5.589B	▲ 17.39%
1999	$4.761B	▲ 48.73%
December 31, 1999	$4.761B	▲ 17.04%
November 30, 1999	$4.068B	▲ 37.06%
October 29, 1999	$2.968B	▼ 2.88%
September 30, 1999	$3.056B	▼ 13.72%
August 31, 1999	$3.542B	▼ 1.88%
July 30, 1999	$3.61B	▼ 3.40%
June 30, 1999	$3.737B	▲ 6.95%
May 28, 1999	$3.494B	▲ 6.17%
April 30, 1999	$3.291B	▼ 13.51%
March 31, 1999	$3.805B	▲ 31.03%
February 26, 1999	$2.904B	▲ 4.16%
January 29, 1999	$2.788B	▼ 12.90%
1998	$3.201B	▲ 224.32%
December 31, 1998	$3.201B	▲ 87.08%
November 30, 1998	$1.711B	▲ 5.68%
October 30, 1998	$1.619B	▼ 14.20%
September 30, 1998	$1.887B	▲ 104.89%
August 31, 1998	$0.921B	▼ 34.35%
July 31, 1998	$1.403B	▼ 3.77%
June 30, 1998	$1.458B	▲ 32.30%
May 29, 1998	$1.102B	▼ 2.22%
April 30, 1998	$1.127B	▲ 14.18%
March 31, 1998	$0.987B	— 0.00%

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:

Note: Market capitalization figures are based on available sources and may differ slightly from actual values, particularly for historical data.