As you probably know, Tesla has made significant investment in the production of batteries for electric vehicles (EVs) and lithium is one of the key metals used to make EV batteries. Assume that Tesla is worried about a surge in lithium prices, thus it wants to use futures contracts to lock in the price of lithium in the next 6 months. Explain how futures contracts can help Tesla hedge against lithium price volatility. Is there any default risk associated with futures that Tesla may face?