If I was unemployed and had a loss on my 1099 B, do I still have to file a tax return?
Yes, if you meet the filing requirement. IRS only sees the proceeds on your 1099-B, not the profit or loss. If your proceeds and any other income are more than the filing requirement, you must file. In addition, if you have losses, the only way to carry them forward to future years is to claim them on your 2018 return.