Forex

Yes, you should report all gains, losses, income and expenses on your tax return. Often times it leads to capital loss carryovers or net operation loss carry backs or forwards when you have negative income.

There are rules that allow no filing if you are under a gross income threshhold. Learn more about that at www.irs.gov.

If the IRS sees large proceeds on a Form 1099 or otherwise, they will think you made a fortune unless you file a tax return showing your losses.