Trading in stock of video game retailer GameStop (GME) was halted briefly Friday, as it soared more than 70 percent. It was due partly to the enthusiastic support of a group of Reddit day traders.

The stock is up more than 250 percent year to date. short-seller Citron research predicted the price would drop. Members of the Reddit board criticized Citron on the Reddit message board.

The hype generated by r/wallstreetbets helped create what’s known as a’short squeeze’. Some investors, known as shorts, essentially bet that a company’s stock will fall. They borrow stock from other investors and sell it – with plans to buy it back when the prices fall and then return it to the original owner.

Gamestop is the most-shorted stock in the market, CNBC says. More than 138 percent of its shares are sold short, making it a prime target for a short squeeze.

Citron said Friday it would no longer comment on the GameStop stock because of’the angry mob who owns this stock’.