Perpetual contract
A futures contract with no expiry in the crypto market. It stays tied to the spot price through the "funding rate" mechanism.
Perpetuals (perps) make up most of crypto derivatives volume. They offer leverage, allow both long and short positions, and have no expiry.
Every 8 hours (varies by exchange), a funding payment is made between longs and shorts: if the perp price is above spot, longs pay shorts. High positive funding can point to an overcrowded long side.