There are two ways Credits turn into XIO Tokens. First, each Credit you attain will earn you 1 XIO. Second, if you manage to reach the XSI Leaderboard, you will receive a Multiplier on your Total XIO Holdings.
Finishing in the Top 10, the amount of XIO Tokens in your wallet will earn 10% interest! Finish in the Top 25, your wallet will earn 5% interest. Finish in the Top 100, your wallet will earn 2.5% interest. Tokens must have been held for 30 days to be eligible for Multiplier.