An engineer checking cable power lines. Image credit: iStock/Thinkstock.

AT&T's (T 0.29%) long history of success, coupled with its sizable dividend yield, has made the telecommunications company a favorite among leading investors and money managers. Its top five institutional shareholders own $36 billion worth of AT&T's outstanding common stock, equating to an ownership interest of 18%.

So, who are AT&T's five biggest shareholders? You can find the answer to this question in the brief slideshow below.

The $15,978 Social Security bonus most retirees completely overlook
If you're like most Americans, you're a few years (or more) behind on your retirement savings. But a handful of little-known "Social Security secrets" could help ensure a boost in your retirement income. In fact, one MarketWatch reporter argues that if more Americans knew about this, the government would have to shell out an extra $10 billion annually. For example: one easy, 17-minute trick could pay you as much as $15,978 more... each year! Once you learn how to take advantage of all these loopholes, we think you could retire confidently with the peace of mind we're all after. Simply click here to discover how you can take advantage of these strategies.

Slideshow data sourced from Yahoo! Finance and on December 10, 2015. Slideshow image credit: AT&T.