The single largest REIT sector by market capitalization, Cell Tower REITs own roughly 50-80% of the 100-150k investment-grade macro cell towers in the United States.

Cell Tower REITs primarily own "macro" communications towers that host cellular network broadcast equipment from AT&T (T), Verizon (VZ), T-Mobile (TMUS), and Dish Network (DISH) but Crown Castle and Uniti Group also have significant investments in fiber and small-cell networks.

While Crown Castle operates exclusively in the United States, American Tower, SBA Communications, and Uniti Group have significant international operations.