How can an investor in a failed EB-5 project keep their priority date?

You cannot keep your priority date if you file a new petition.

I do not believe that USCIS can revoke your I-526 approval, but getting your I-829 approved in two years' time may prove to be impossible. The only current remedy is refiling, which would reset the priority date.

Unfortunately, the priority date in the EB-5 category is not transferable. However, if you have already entered the United States on a conditional green card, there is an argument to be made that because you have already used a visa number allotted to you, once the new I-526 is approved you could re-adjust immediately. Of course, this is just an argument that could be made and there is no guarantee that it will be successful.

A separate priority date will be issued on the new I-526 petition. There is no portability with respect to a new I-526. You may always ask United States Citizenship & Immigration Services (USCIS) to, as a matter of discretion, assign the previously noted priority date. As for an SEC investigation, maybe you should reach out to the SEC to see if you can assist them in the fraud investigation.

I am not aware of any statutory regulation regarding being a victim of fraud. However, if you write to USCIS, I am sure they may have an administrative remedy, as this happens too often.

If your case was filed and approved, you should get to keep your priority date. If revoked, that could be a problem.