I recently invested in stock and sold the stocks which i bought, both happened in Jan 2015. This was my first ever trading with stocks in US and was a new individual brokerage account with fidelity.

However after the sale when I tried to transfer the funds to my bank, fidelity withheld 28% in taxes. They said I had a missing w9/w8 form on file.

Now I am not sure which form to file, W9(residents) or w8(international). I am on an F1 visa and have been in MD for close to 3 years now. As per my opinion it should should be W8 since I am on a student visa still but since I have a US address and stay in US I might qualify for W9 which seems to be the more convenient way.

But just that I do not want to go wrong here so that issues don't crop up later.
Please advise.