Update (Nov. 1, 15:03 UTC): Deribit will reimburse over $1.3 million in losses from the BTC index calculation data issue witnessed at 21:00:00 UTC on October 31, 2019.

Another flash crash has occurred for bitcoin (BTC), this time appearing on the Coinbase Pro and Deribit exchanges.

At 19:55 UTC on Oct. 31, BTC’s spot price dipped from $9,260 to $9,055 in quick succession on Coinbase’s exchange for professional traders.

An hour later, Deribit, a futures and options exchange for BTC, saw futures prices drop from $9,150 to $7,720 before bouncing back above $9,000 within minutes.

The move caught traders unawares as multiple orders were executed in the process.

Crypto trader @Crypto_boy1 took to Twitter to slam Deribit for telling customers that trades would not be rolled back and that they should manage positions accordingly.

“It’s over. I would withdraw all funds and never use this exchange again If I was a user” he said.

5-minute chart

As seen above, BTC dropped to a low of $7,720 on Deribit, sending shock waves throughout the derivatives market. Liquidations shot through the roof on Bitmex, for example.

However, in an official response on the same thread, Deribit said it would attempt to rectify the incident by changing the price of stop-loss trades to a fixed BTC level, depending on the product.

“Equity will be brought back to the pre-incident level, around index price $9,160,” the exchange said.

5-minute chart

An hour before Deribit’s incident, Coinbase Pro users also experienced problems as stop-loss orders were “deleted” right before BTC’s sharp drop from $9,260 to $9,055.

According to a user of CoinDesk’s Dojo trading forum who goes by the handle Radyohead, the price dropped below their stop-loss order, yet no sale was executed:

“Coinbase crashed as far as I can see. And it deleted my Stop Loss as it happened, nothing sold for me despite the price being lower than where my stop was.”

Prices have since rebounded, currently changing hands for $9,145, while the issues on both exchanges appear to be resolved.

Disclosure: This author holds no cryptocurrency at time of writing.

Ride image via Shutterstock; Charts via TradingView