Perpetual futures
A futures contract with no expiry, kept near the spot price by periodic funding payments between longs and shorts.
Perpetuals carry most of crypto's trading volume. Nothing is delivered; the position's gain or loss is settled continuously against the mark price in the margin posted. Their capital efficiency and easy shorting make them popular, and the leverage they concentrate makes them the source of most sudden moves. Coinmico measures perpetual volume separately from spot.