Michael Dell's $80 million investment no one knew about could be worth as much as $4 billion

Dell founder Michael Dell has quietly invested over $80 million in various local TV stations since 2011 - and it could soon end up returning as much as $4 billion to the PC mogul.

According to a WSJ report on Wednesday, Dell currently controls a group of broadcasters that collectively own spectrum licenses that's worth $4.2 billion, based on prices set by the FCC.

Dell's investments were made through his investment arm MSD Capital, which created a company called OTA Broadcasting to control all the TV stations.

Some of the stations under Dell's control include the Spanish-language channel Azteca America and a New York-based Korean TV channel. He also owns 11 local stations in the Pittsburgh area, which collectively cost him roughly $7.3 million to invest, but is now estimated to be worth $1.47 billion.

Dell's investment in TV stations is part of a broader activity called spectrum speculation. The investments were likely made in anticipation of the upcoming FCC auction, in which spectrum licenses will be sold to wireless broadband carriers like AT&T and Verizon, who need additional airwave frequencies to meet the soaring demand for its services.

Other notable spectrum speculators include Fortress Investment Group and Blackstone Group, the WSJ report said. The FCC auction is set to take place later this year.

But the report also noted that it's unlikely Dell will get the full $4.2 billion from the auction. The FCC sets the opening bid at the highest possible price to get as much participation as possible, and runs the auction in the style of a Dutch auction in which the price is dropped until the buyer is found.