I'm trying to find out the difference between execution price of stocks versus mutual funds. I can sell stocks at any given minute the market is open. However for mutual funds, it says "next closing market price".
I see. This is because the price of mutual funds is calculated at the end of each day, based on the closing prices of the underlying securities (ie the stocks and investments held by the mutual fund). This number is called the NAV (net asset value). It is actually the assets - liabilities divided by number of shares. It cannot be calculated until the market closes each day because the movement of the underlying stocks is not determined until market closes. Traditional mutual funds don't fluctuate/trade throughout the day like stocks do. Closed-end mutual funds (aka ETF's) DO trade throughout the day like a stock and their price fluctuates accordingly.