M-Money

C-Commodity

M-Money 

The way capitalists maintain and increase their wealth is by M-C-M. They start with money to be able to purchase commodities and labor which means this allows for production to move forward. Workers are then paid less than the value that they create, this is called surplus value and then their work gets sold on the market to make more money and capitalists end up with the money. Over time the capitalist class maintains and increases their wealth over time following this cycle.