If you are referring to total supply which I think you are because most of the times it can still be called maximum supply; hence the total supply is 10,000,000 COMP while the circulating supply is 2,561,279 COMP, it is right there on the coinmarketcap website. Also, as to the reason why a coin will increase massively can be attributed to the news or event the team bears which could be a platform upgrade, mainnet, new partnership, achieving a major milestone, endorsements, new exchange listing and it goes on. So one or more of these can make a coin to increase massively in price.