United States Oil Fund is a publicly traded commodity pool structured as a limited partnership that enables individual and institutional investors to gain exposure to crude oil prices without direct physical ownership or futures trading. The fund invests primarily in light, sweet crude oil futures contracts and related derivatives traded on exchanges including NYMEX and ICE Futures, with collateral held mainly in U.S. Treasury securities and cash equivalents; it does not leverage its assets or make cash distributions. USO generates returns through capital appreciation on its oil futures and derivatives positions, plus interest and dividend income earned on its collateral holdings, while operating under strict regulatory position limits and constraints set by the CFTC and SEC that affect its growth and diversification strategy.