United States Oil Fund (USO) is an exchange-traded commodity fund structured as a Delaware limited partnership that gives retail and institutional investors exposure to crude oil prices without physically owning oil. USO shares trade on NYSE Arca like a stock. Rather than holding physical crude, USO primarily holds NYMEX WTI near-month futures contracts, with U.S. Treasuries and cash as collateral. The fund's goal is for the daily percentage change in its NAV per share to closely track the daily percentage change in the price of the near-month WTI futures contract. USO is managed by its general partner, United States Commodity Funds (USCF), which handles all investment decisions — USO itself has no employees. Investors use USO for two main purposes: gaining indirect exposure to crude oil price movements through a standard brokerage account, or hedging against adverse oil price moves. USCF earns revenue by charging USO a management fee of 0.45% per annum on average daily net assets, so USCF's income scales directly with USO's AUM. A key structural feature — and risk — is the monthly "roll," where USO sells expiring near-month contracts and buys next-month contracts. When the futures market is in contango (future contracts priced above near-month), this roll repeatedly sells cheap and buys expensive, creating a performance drag relative to spot oil prices. USO shares are created and redeemed through 13 authorized participants in blocks of 100,000 shares at NAV, with an arbitrage mechanism designed to keep the market price close to NAV.