I'm saying a Fraud conviction is not the same a stealing. I'm completely ok with a conviction for fraud, provided that the conviction and sentencing is based upon that fraud.
I would characterise robbing a bank, placing a bet and returning the funds as theft.
However if you entrusted me with $500 and I gambled and paid you back when you wanted the $500, I would not say that is theft. If I had promised not to gamble, then it would have been fraudulent.
Except SBF didn't gamble away the money (still a criminal offence if he did); he spent it on lavish goods and apartments, with a lot of political donations. The very definition of fraud is deception, misappropriation, and loss to the users, all of which did happen.
In between placing a bet and returning the funds, the customer's funds were totally non-existent hence the loss to the user. That things later worked out after some years does not take away the misappropriation and that there was no actual money where it was meant to be at that moment, hence a fraud.
You can characterize things however you want. But "theft" and "fraud" are extensively defined concepts in caselaw. Fraud, specifically, is legally defined quite differently than what most people think the word means in common usage and your example here does not have much relationship to it.
Well I have only seen media reports alleging theft, such as the article linked, they don't necessarily have to conform to legal definitions. A cynical person might suggest that perhaps media coverage deliberately chooses between colloquial, legal, and scientific definitions at will depending on the narrative they would like to create.
Was there ever a charge of theft in the legal sense filed in court?