You still have to file, in stock trading, the IRS only sees your sales on the 1099B, so you need to provide the "cost basis". I decided not to file one year, and I got a TAX BILL for over a million, and I lost $$$! I promptly filed, and cleared that up. Yes it does suck! el surdo
This is good to know... i have heard many daytrading irs horror stories. For losses from retail accounts (scottrade, tradestation etc) it carries over 3 years corect? or is that something else?