Foreign currency losses are reportable as ordinary loss under Code Section 988.
Per IRS: Except as otherwise provided in this section, any foreign currency gain or loss attributable to a section 988 transaction shall be computed separately and treated as ordinary income or loss (as the case may be).
You would report the loss on line 21 of Form 1040 (Other Income or Loss), as this sounds like an investment issue. It would be a Forex loss only you qualify for trader tax status (business treatment), and in that case you would report the Section 988 ordinary loss on Form 4797, Part II ordinary gain or loss.
