Thank you very much @Mike9241 ! I am not sure why I am under the impression that if someone's only income is the trading income, if they don't make the mark-to market election, their business expense on schedule C will be carried forward and can't deducted against the capital gain in the same year. If they make the mark-to-market election, their income will become ordinary income but still not earned income. Not sure if it has to be earned income but I don't see it is being advertised anywhere as a benefit (don't have to get other W2 or contractor jobs) of mark-to-market election.
Then if I don't really lose money when trading, the main benefit for me to make the mark-to-market election would be that I would be able to get the 20% Qualified Business Income Deduction if I make less than the income limit because QBI doesn't apply to capital gain?
