Both Binance and Coinbase suffered technological issues on Wednesday — the same day Bitcoin (BTC) crossed the $20,000 price threshold for the first time. Binance related its issues to the number of people surfing the exchange. 

Changpeng Zhao, or CZ, Binance’s CEO, tweeted on Wednesday at 2:13 pm UTC:

“#Bitcoin just popped. Experienced some scaling issues. Should be fixed for now. Underestimated demand. Adding A LOT more ‘servers’ still.”

An update from CZ came about half an hour later, revealing improvements, as well as a dramatic surge in users on the platform. “Still some latency issues here and there. Working on it, all hands on deck,” he tweeted, adding: “Bitcoin goes up 5%, traffic goes up 30x.” By 2:56 pm UTC, CZ noted the situation as resolved.

Bitcoin broke above $20,000 for the first time ever at 1:42 pm UTC on Dec. 16, reaching a price near $20,800 by 2:14 pm, according to TradingView.com data.

At 2:45 pm UTC, Coinbase also reported issues via its status page. “Coinbase.com is experiencing connectivity issues,” the exchange posted. The exchange said that the problem was resolved at 4:27 pm.

Coinbase has a history of technical difficulties during periods of high traffic, commonly referencing “connectivity issues” as the cause. Brian Armstrong, Coinbase’s CEO, recently said the exchange is working toward solutions for handling high website engagement.