4. AT&T Wireless Services
Background: AT&T Wireless debuted in a public offering in April 2000, raising a whopping $10.6 billion. The IPO was meant to separate the telecom company's mobile and landline phone business one month before the dot-com bubble bursting.
In 2004, AT&T Wireless was acquired by Cingular, a joint venture between SBC Communications and BellSouth. SBC also acquired the original AT&T the following year and the wireless provider was eventually folded back in. The entire conglomerate was renamed AT&T (T - Get Report).
Last year, AT&T's planned acquisition of T-Mobile from Deutsche Telekom was denied by the Federal Communications Commission and Department of Justice. AT&T said publicly in December that it would end its bid for the rival.Stock performance: Shares of AT&T are up 11.18% this year, boosted by strength in its wireless business. AT&T's stock is down 0.12% to $33.62 Monday.