The other $10,000 is not subject to any tax.
Whether or not you owe tax depends upon how the investment was classified. If it was in a retirement account that receives tax shelter treatment, then no tax is owed. If it's not sheltered from taxes, then you will have to pay tax on the "gains" that your investment earned, thus the "capital gains" tax rates that exist, as they are different then ordinary tax rates on earned income. To determine your rate, you would have to add the "gain" income to your other income to determine where you would fall in the bracket. If this is the only income you have, then 0 tax would be owed.
no tax.
it's not interest, btw
let's say I invest 10K into the stock market, and it earns me exactly 10%, and I let it sit for 3 years, and I now have 13,310, and I sell it all, and have no other source of income for the year I sell it, how much money in taxes will I owe?
