You should sleep faster
Though I don't really think that the amount of sleep actually matters here. In other words, if you start sleeping half as much (say, 4 instead of 8 hours), this won't make you rich on its own. I'd rather say that depriving yourself of a healthy amount of sleep will actually make you less efficient. The wealthiest people are not very young overall (Warren Buffett is 86, Bill Gates is 61 already and he doesn't look very healthy overall) but elderly people just happen to sleep less
Gates kinda seems to be troubled by pangs of conscience