The popular stock investment app Robinhood has stopped supporting the purchase of new shares on a handful of stocks supported by the recent Reddit fueled frenzy.

Robinhood messages posted to various company pages like GameStop, AMC and Nokia, inform users that the stock is not supported on Robinhood, or not available for purchase. Some are allowed to sell.

Robinhood has not issued any guidance on the halt and it’s unclear how long it will last. The halt was first noticed around 8:30 a.m. on Thursday.

UPDATE: Robinhood released a statement as markets opened:

Our mission at Robinhood is to democratize finance for all. We’re proud to have created a platform that has helped everyday people, from all backgrounds, shape their financial futures and invest for the long term.

We continuously monitor the markets and make changes where necessary. In light of recent volatility, we are restricting transactions for certain securities to position closing only, including $AMC, $BB, $BBBY, $EXPR, $GME, $KOSS, $NAKD and $NOK. We also raised margin requirements for certain securities.