Suddenly, I have a curious question: if I make quite some money from stock market this year, obviously, I need to pay additional tax to IRS/State. But that is not my question.
My question: I have regular salary job, and employer withholds social security tax/medicare tax based on my salary. Now suddenly, my income has increased due to stock capital gain, how will the extra income affect social security tax/medicare tax? Do I also need to pay additional social security tax/medicare tax?
Just curious how it works? Does social security tax/medicare tax apply to capital gain? If not, what if someone is a full time stock trader (he has to pay social security tax/medicare tax, how does he pay)?
Thanks.
