<prompt> Human: Hello guys I wanted to try out stock investing. I put 1000 dollars into stocks... Then after a couple months last year I sold them for 900. So I lost money.. I forgot to claim them on my tax return. What should I do?Edit: Thanks for the help everyone! I was just worried because I thought I saw someone on here say before that the IRS only sees the selling price not the purchase price if you forget to claim and you can get audited. Ill make sure to deduct my new losses this coming year  <response>: You could file an amended return to get back your marginal tax rate on a 100 loss, or about 25. Or, you could not worry about it. 