Bitcoin jumps to $56K on Bitfinex in a flash rally. Can someone confirm or explain this phenomenon and what happens in these cases if sell orders get executed.

https://beincrypto.com/bitcoin-spike-liquidity-dangers-crypto-exchanges/

I found this a bit shocking, hadn't heard about this in a long time - used to hear an example here and there several years ago. I am curious if sell orders with "dream-price" were actually executed and whether the exchange honors those orders. If it does, then it's a pretty sweet deal for those sell orders - making an instant 100% above market, or, can double the holding instantly.

Can anyone confirm this and explain how that happens? Because the downside is also possible but good news is that nobody sets a sell order on down price, someone have to be out of mind to set a sell order when price declines let's say 50%.

Interesting times. The article states lack of liquidity as a major reason for the flash rally and liquidity is becoming scarce across exchanges. Do you guys expect this to happen more often? Should I set my sell orders? :)