What is Mutualized Proof of Stake (MPoS)?

Mutualized Proof of Stake (MPoS) is a consensus mechanism that is used by the Qtum blockchain. Unlike Proof of Stake (PoS), MPoS divides each block reward between the block producer and the nine previous block producers. A block's producer receives 10% of the block reward immediately, and the remaining 90% is distributed after waiting for 500 blocks. This is done to disincentivize malicious attacks on the network.