Buying and selling on popular cryptocurrency exchange Coinbase was disabled Friday.

The entire market for digital currencies was under intense pressure with bitcoin trading down 20% on Coinbase's GDAX exchange.

Buys and sells on Coinbase, the largest cryptocurrency exchange in the US, were disabled for a little over two hours Friday amid a massive cryptocurrency sell-off.

"Due to today's high traffic, buys and sells may be temporarily offline, the comapny said in an alert posted at 11:35 a.m. ET. "We're working on restoring full availability as soon as possible."

The exchange had things back up and running at 1:44 p.m. ET, according to its site.

The outage occurred while major cryptocurrencies were trading in the red. Bitcoin was down more than 20% on Coinbase's GDAX exchange at the time of writing. It was trading at $12,650, down from an all-time high above $19,000 earlier this week. In total, the cryptocurrency market has shed more than $140 billion from its market capitalization over the last twenty-four hours.

Coinbase has struggled to fully function under high-traffic and volatile moments in the crypto-market.

Buys and sells of bitcoin cash, another cryptocurrency, were disabled on Coinbased Tuesday. The company said in a blog post it disabled trading because of "significant volatility."

On December 12, the company halted trading of litecoin and ether as the two cryptocurrencies reach all-time highs.