Same here with USO. I didn't fully understand it at the time, so I used USO because you can buy and sell like a stock. I thought that it would just be a proxy f

Same here with USO. I didn't fully understand it at the time, so I used USO because you can buy and sell like a stock. I thought that it would just be a proxy for investing in oil futures contracts, similar to how buying SPY is basically a proxy for buying a weighted basket of stocks in the S&P. I learned that I was wrong the hard way (luckily didn't wager anything I couldn't afford to lose).