can I claim losses from a private equity investment that was found to be a fraud?

[xmasbaby0]

No.   Unless your loss was due to victimhood of a Ponzi scheme, it is not deductible.

[Opus 17]

So, "investment" -- maybe.  Investment losses are deductible against investment gains.  Theft losses are not deductible.  Sometimes it is difficult to determine whether a loss is from a theft or an investment loss.  The IRS recently issued some new rules.  If you have questions, it would be best to discuss with your own tax professional with whom you share all the details.

https://www.slatterycpa.com/irs-clarifies-theft-fraud-loss-deductions-scams/

https://www.taxpayeradvocate.irs.gov/news/nta-blog/irs-chief-counsel-advice-on-theft-loss-deductions...

https://www.thetaxadviser.com/issues/2025/feb/taxpayer-denied-theft-loss-deduction-for-investment-lo...

https://www.forbes.com/sites/matthewroberts/2025/03/19/irs-surprises-taxpayers-with-new-ruling-on-th...