The U.K.-based exchange said it would be halting withdrawals and dissuaded customers from making deposits following what it implied was a security lapse. Still, some have argued that this could be an excuse for a larger liquidity problem after the weekend's big drop in bitcoin's price.
"We have reason to believe that one of Bitstamp's operational wallets was compromised on January 4th, 2015," the company wrote in a message on its website.
Bitstamp maintains that less than 19,000 bitcoin (about $5.1 million at Monday's price) were lost after the security lapse, according to a spokeswoman. The exchange's customers can also "rest assured" that they will be able to recover the full amount of their cryptocurrency stored with Bitstamp before the suspension, CEO Nejc Kodrič said in a statement provided to CNBC.
Here's Bitstamp's full Monday morning message: