Hi Kim! When you sell an investment such as stocks, bonds and mutual funds, they are taxable if you have a gain - that is if you sold it for more than you bought it for. For example, if you bought a stock valued at $1,000 and later sold it for $1,200, then you would pay tax on the gain of $200. The gain on the transaction is taxable in the year you sold, whether you withdraw the money from the account or not. I hope that helps!