Not sure what kind of answer you expect here. Fairly broad conspiracies in the financial world exist sometimes, see the famous LIBOR case that involved bankers talking to each other in order to "fix" rates etc.
But far more it's the case that there are bunch of gullible "experts" near the center of some bubble (be it a bubble based on some core fraud), experts who could only be convicted under some Soviet-like law standards ("undermining the national economy" and the like), which aren't part of the Western law codes. If you want some example of the latter (I mean gullible experts):
The Swiss bank Union Bancaire Privée explained that because of Madoff's huge volume as a broker-dealer, the bank believed he had a perceived edge on the market because his trades were timed well, suggesting they believed he was front running.
And from one of the related articles:
In April 2010, Judge Thomas Griesa, of the U.S. District Court for the Southern District of New York dismissed a lawsuit by Tremont Group investors against Tremont's auditor, KPMG, which charged that KPMG had failed to discover the fraud in its audits of Tremont and was therefore liable to the investor. Judge Griesa held that KPMG could not be sued, because there was no intent to deceive. He wrote: "Merely alleging that the auditor had access to the information by which it could have discovered the fraud is not sufficient."
I'm also reminded here that in the Enron scandal, their auditor [company] went out of business. As for conviction of said auditor, it was unanimously overturned by SCOTUS...
Rehnquist's opinion also expressed grave skepticism at the government's definition of "corrupt persuasion" – persuasion with an improper purpose even without knowing an act is unlawful. "Only persons conscious of wrongdoing can be said to 'knowingly corruptly persuade'", he wrote.
I personally don't know a lot about the FTX case to comment in detail on that. But from what I read it's [allegedly] much closer to a Madoff type of swindle than something else. I.e. one guy who moved his customers' money to his own accounts, or at least to some accounts they didn't agree to beforehand ("Alameda Research").
According to FT's summary (of last year):
The business [FTX] was run more like a feudal court than a modern company, according to the employees. Decision-making and knowledge of the company’s affairs was restricted to Bankman-Fried and a handful of close friends in their late 20s, many of whom lived together in a luxury penthouse in the Bahamas. Loyalty was prioritised above all else.
The initial verdict from John Ray III, the veteran insolvency professional brought in to run the business, was devastating. “Never in my career have I seen such a complete failure of corporate controls and such a complete absence of trustworthy financial information as occurred here,” said Ray, who previously helped wind down Enron, the failed energy group.
But hey, FTX was a company nominally based in Bahamas after all. Yeah, it is more questionable why Silvergate, a US bank, was allowed to have FTX as its main customer with little to no questions asked about the soundness of that. But the US is well known for not regulating smaller banks much.