I think some details are important.
If the loss is a personal loss, then the loss is not deductible for Federal taxes.
However, it may be deductible on your state taxes. Don't take this next statement as gospel, but here is a site that explains it could be deductible in CA: https://www.caltax.com/forums/topic/virtual-currency-scam/ You should check with your state to determine if it is deductible on your state taxes.
If your loss is not a personal loss, rather a loss by a business, the situation may be different. I personally don't know how that would be handled.
