> If it's 1099 income, they know it for the reason that the 1099 gets filed with the IRS, as well as a copy going to you. 1099s have the wrong cost basis infor

> If it's 1099 income, they know it for the reason that the 1099 gets filed with the IRS, as well as a copy going to you. 1099s have the wrong cost basis information for ESPP and vested RSU shares, so the IRS does not know what the correct tax is when those are involved.