I think that key EA orgs (perhaps collectively) like the Center for Effective Altruism/Effective Ventures, Open Philanthropy, and Rethink Priorities should consider engaging an independent investigator (with no connection to EA) to try to identify whether key figures in those organisations knew (or can reasonably be inferred to have known, based on other things they knew) about the (likely) fraud at FTX.
The investigator should also be contactable (probably confidentially?) by members of the community and others who might have relevant information.
Typically a lawyer might be engaged to carry out the investigation, particularly because of professional obligations in relation to confidentiality (subject to the terms of reference of the investigation) and natural justice. But other professionals also conduct independent investigations, and there is no in principle reason why a lawyer needs to lead this work.
My sense is that this should happen very promptly. If anyone did know about the (likely) fraud at FTX, then delay potentially increases the risk that any such person hides evidence or spreads an alternative account that vindicates them.
I'm torn about whether to post this, as it may well be something that leadership (or lawyers) in the key EA orgs are already thinking about, and posting this prematurely might result in those orgs being pressured to launch an investigation hastily with bad terms of reference. On the other hand, I've had the concern that there is no whistleblower protection in EA for some time (raised in my March 2022 post on legal needs within EA), and others (e.g. Carla Zoe C) have made this point earlier still. I am not posting this because I have a strong belief that anyone in a key EA org did know - I have no information in this regard beyond vague speculation I have seen on Twitter.
If you have a better suggestion, I would appreciate you sharing it (even if anonymously).
Epistemic status: pretty uncertain, slightly anxious this will make the situation worse, but on balance think worth raising.
Relevant disclosure: I received a regrant from the FTX Future Fund to investigate the legal needs of effective altruist organisations.
Edit: I want to clarify that I don't think that any particular person knew. I still trust all the same community figures I trusted one week ago, other than folks in the FTX business. For each 'High Profile EA' I can think of, I would be very surprised if that person in particular knew. But even if we think there is only a 0.1% chance that any of the most influential, say, 100 EAs knew, then the chance that none of them knew is 0.999^100, which is about 90.4% (assuming we naively treat those as independent events). If we care about the top 1000 most influential EAs, then we could get that 90.4% chance with just a 0.01% chance of failure.
Edit: I think Ryan Carey's comment is further in the right direction than this post (subject to my view that an independent investigation should stick to fact-finding rather than making philosophical/moral calls for EA) plus I've also had other people contact me spitballing ideas that seem sensible. I don't know what the terms of reference of an investigation would be, but it does seem like simply answering "did anybody know" might be the wrong approach. If you have further suggestions for the sorts of things that should be considered, it might be worth dropping those into the comments.