Yes. . .you can deduct short-term /long-term losses too. . .you just have to fetch this stuff--these figures-- from your brokerage house when you get ready to file your taxes in April, the next year. Securing these figures/reports from etrade/TD AMER. or Schwab (or whomever) will certainly be important.
Remember: loss or profit comes when you SELL your securities. . .sell date, important and certainly the purchase date (this determines whether it is short term--less than one year--or long term, more than one year transaction!!