Ten percent PER DAY? And a bunch of suckers that didn't understand the terms (even though they were assholes).
And it's premeditated, too! He knew the setup from the beginning! What was he gonna do if these guys were actually nice? It doesn't sound like he was thinking about the massive interest until it all came crashing down. Would doing a series of one day lend and returns (so the interest doesn't compound on itself) even occur to him?
Holy crap, full on villain protagonist here. Loan sharks have their representation.