AMT vs SPG Comparison

American Tower owns and operates about 150,000 wireless towers throughout the US, Asia, Latin America, Europe, and Africa. It also owns and/or operates 30 data centers in 11 US markets after acquiring CoreSite. The company's customer base in the tower business is very concentrated, with most revenue in each market generated by the top three or four mobile carriers. The company operates more than 40,000 towers in the US, which accounted for about half of total revenue in 2025. Outside the US, American Tower operates about 47,000 towers in Latin America (dominated by Brazil), 33,000 towers in Europe, and 28,000 towers in Africa. American Tower operates as a REIT.

Simon Property Group is the largest retail real estate investment trust in the United States. Its portfolio includes an interest in 254 properties: 114 traditional malls, 108 premium outlets, 14 Mills centers (a combination of a traditional mall, outlet center, and big-box retailers), six lifestyle centers, and 12 other retail properties. Simon's portfolio averaged $736 in sales per square foot over the trailing 12 months. The company also owns a 22% interest in Klépierre, a European retail company with investments in shopping centers in 14 countries, and joint-venture interests in 33 premium outlets across 14 countries.