Billionaire Ryan Cohen's investment company bought 100,000 shares of GameStop Corp, according to a regulatory filing on Tuesday, sending the videogame retailer's shares 16% higher in extended trading.

The purchase takes Cohen's stake in the company marginally higher to 11.9%, with the total number of share owned at 9.1 million.

Shares of GameStop closed up 30.7% at US$123.14, registering their biggest one-day percentage gain since March 25 last year, with trading volumes soaring and likely squeezing bearish investors who sold the stock short.

There was no clear reason for the rally during normal trading hours, according to analysts.

Cohen, who co-founded online pet products retailer Chewy and is GameStop's chairman, earlier this month said he now owns nearly 10% of Bed Bath & Beyond and wants the home goods retailer to explore alternatives including a full sale of the company. 

(Reporting by Uday Sampath in Bengaluru; Editing by Shounak Dasgupta)

Correction:

The headline of this story previously indicated Ryan Cohen was a U.S. billionaire. Although he conducts business in the U.S., Cohen was born in Canada.