STX, the cryptocurrency that power’s the Stacks protocol, a layer-2 scaling solution built on top of Bitcoin that aims to bring smart-contract programmability to the Bitcoin ecosystem, is pulling back on Monday after seeing a big pump on Sunday. STX/USD was last changing hands around $0.5750, down around 8% on the day and lower by around 30% versus the nine-month highs it hit earlier in the session in the $0.84 area.