In the context of a funded MSA within a proprietary trading firm, "skin in the game" refers to the level of personal investment or risk that the has in the account.

It is a measure of the trader's commitment and accountability for the performance of the account. A trader with a significant amount of skin in the game, for example, has a larger personal financial stake in the account's success. This can be a positive indicator of the trader's dedication and discipline when making trades.

This investment is typically used to fund the traders' trading activities and is a way for the traders to align their interests with those of the firm. By having "skin in the game," traders are incentivized to perform well, as their personal financial well-being is directly tied to the success of the firm. This is in contrast to a traditional employment model, where traders are not financially invested in the firm and may not have the same level of motivation to perform well.