Boostcoin (BOST) claims to be the first hybrid PoW/PoS X13 altcoin. The PoW phase was set to have a block reward of 515 coins per block - a sixty second block target and a total supply of 11.7 million coins. The total supply of coins is limited to 40 million including the PoS phase which has an interest rate of 10% annually. There are continuing rewards from PoS blocks towards the BoostCoin foundation and there was a 1% premine.