It is not much different from reporting capital gain: you'll get 1099 from
your brokerage service provider, and you need to figure out the base of the
investment that incurred loss and calculate the loss. You can only claim $
3000 capital loss ($1500 if married file separately). Any loss more than the
limit can be carried over to the next tax year. See this for more
information: http://www.irs.gov/publications/p550/ch04.html#d0e14660
You should also be aware of the wash sale rule if you trade th