FTX has put out a press release announcing a “process for voluntary return of avoidable payments.” This may be a useful option for grantees looking to urgently return any FTX-associated funding rather than wait for the bankruptcy process to play out. But anyone interested in returning money should keep in mind that in order to avoid being subject to redundant clawbacks or other legal claims later, it’s crucial to receive proper release-of-claims paperwork in exchange for returning funding. I strongly recommend you consult with a bankruptcy lawyer before starting this process. The Open Phil legal team is putting together a list of legal service providers for grantees who want to explore this option; we’ll follow up after the holidays with more information.
For some who are planning to return funds, there could be tax advantages to doing this prior to December 31. (I should note that I have no inside knowledge about the process above and whether returning the monies prior to December 31 is even possible.)
In many parts of the US, you can get a referral to a lawyer for an initial consult at a low cost, and I think for some individuals and for-profits it may be worth a quick consult with a tax lawyer to ask whether there are different tax consequences for you of returning funds before vs. after December 31. I agree with Molly that you will want to work with a bankruptcy lawyer if you decide to return the money.
While I can't give any legal advice other than "consult a lawyer who can represent you," one potential scenario that comes to mind involves any US persons for whom the grant would be considered self-employment income that would count for 2022. Having self-employment income in 2022 and an offsetting business loss when the funds are repaid in a later tax year could potentially lead to a situation where you have to pay self-employment taxes in 2022 (i.e., Social Security/Medicare) and won't get a benefit from the later-year repayment (for self-employment tax purposes). I'm not confident in that assessment, but do encourage people who think they would have to pay self-employment tax on an unreturned grant to consider talking to a tax lawyer about that specific point very soon.