A South Korean cryptocurrency exchange, Bithumb, apologised on Saturday after mistakenly transferring more than $40 billion worth of bitcoin to users.

The error briefly triggered a selloff on the platform.

Bithumb said it accidentally sent 620,000 bitcoins, currently valued at more than $40 billion, to users.

The mistake occurred on Friday during a promotional event.

The exchange blocked trading and withdrawals for the 695 affected users within 35 minutes of discovering the error.

According to AFP, Bithumb intended to send about 2,000 won ($1.37) to each customer as part of the promotion.

Instead, it mistakenly transferred roughly 2,000 bitcoins per user.

“We sincerely apologise for the inconvenience caused to our customers due to the confusion that occurred during the distribution process of this (promotional) event,” Bithumb said in a statement released Saturday.

The platform announced it had recovered 99.7 percent of the mistakenly sent bitcoins.

It stated that it would use its own assets to fully cover the amount that was lost in the incident.

Bithumb admitted the error caused “sharp volatility” in bitcoin prices on the platform.

Some recipients sold the tokens, leading to the price drop.

The exchange said it brought the situation under control within five minutes.

Its charts showed the token’s price briefly fell 17 percent to 81.1 million won on the platform late Friday.

The platform stressed that the incident was “unrelated to external hacking or security breaches”.

Bitcoin, the world’s biggest cryptocurrency, sank this week.

The decline wiped out gains sparked by US President Donald Trump’s presidential election victory in November 2024.