Long story short, I invested some money for my mom using the proceeds of a car I sold for her, using my own brokerage account, since that was the easiest thing to do. The idea was to hold the shares long term, and I would eventually transfer the shares to a new brokerage account I would set up for her. Unfortunately, (or fortunately, depending on how you look at it) $500 of those shares were in a company that was acquired last year and I suddenly had $4400 in cash in my brokerage account from that buyout. I kept 15% of it to cover Long Term Gain taxes and gave her the rest (she was quite happy!) but what I didn't expect was it put my AGI at a higher level, and that limited my allowable loss in a rental property I own. To the tune of $1600 less on my refund!
Not trying to throw my poor mother under the bus, but is there a way I can tell the IRS that this gain actually belongs to her instead? It was her money that I invested, and she got the proceeds. I had no benefit from it.