The cftc has ~700 employees total, not just investigators, total employees.

They do not typically proactively investigate firms, they do so when there is evidence of a violation, usually after complaints of losses are made.

Also, due to resource constraints they tend to prioritize investigations by the number of people impacted.

FTX frankly doesn’t meet either of those bars. By the time people would complain about losses the whole thing unravelled and as big a topic it is on hn not many people are actually impacted by it. At least compared to some of the big gold grifts that are out there.