The idea that Sam was just a risky investor is the story Sam wants to tell. But he already told that story in court, and it was rejected.. because the evidence doesn't support it.
I'm sure both SBF and Madoff originally thought they would be able to make enough money to cover up the theft.
I don't really think that has the moral conclusion people try to imply though. Thinking they could get away with it as a permanent secret gap that no one need ever know about is actually a worse moral character.
From what I’ve seen about SBF, it does seem like he has a very high risk tolerance, was betting big to win big, and thinking the reward was worth the risk.
Heck it's almost like this describes crypto itself