It is unclear what this means for WWE, though, given McMahon already spends nearly all of his time on running the company.
Reports from Brad Shepard and David Bixenspan earlier this week showed that McMahon had created Alpha Entertainment and registered multiple trademarks, including for "UrFL" (as in Your Football League), "United Football League", "UFL" and "For the love of football".
In case you didn't know..
President Donald Trump is a longtime McMahon family friend and many people are speculating that the new organization would have the full backing of Trump, especially given his less than supportive tweets aimed at the National Football League the past few months.
The XFL, a joint venture between WWE and NBC, originally debuted in 2001 but only last one season, as WWE and NBC lost approximately $35 million each, after taxes, on the league, according to Darren Rovell.
WWE stock was at a high of $32.27 Dollars earlier this morning, but fell to $31.87 by the end of the business day.
Vince McMahon's Alpha Entertainment has filed for five trademarks to "XFL".More news: Mourinho: Bristol City a bit 'lucky'
Filings with the U.S. Securities and Exchange Commission revealed McMahon sold 3.34m shares in WWE which will be used to fund a separate company - Alpha Entertainment - that is exploring "investment opportunities across the sports and entertainment landscapes, including professional football".
On Thursday, McMahon sold 3.34 million shares of WWE, which is worth $100 million.
McMahon's sale represents ~4.3% of the company's total outstanding Class A and Class B common stock.
But securing a trademark is a far cry from selling off a huge amount of stock in the business McMahon has spent a lifetime building.
The XFL also tried to combine the WWE and National Football League, with mixed results.