ELI5: Explain Like I'm 5

Stock fund

A stock fund is a type of investment that lets you pool together your money with other investors, which is then used to buy and sell stocks. Stocks are pieces of ownership in a company. When you buy stock in a company, it means you own part of the company. When the company does well, then the value of the stocks go up, which means that your investment in the stock fund increases (goes up) in value too.