The financial turmoil has amplified the risks of financial derivatives such as futures and options, and the huge volatility has led to a sharp rise in the cost of options. Now, the option, originally used as a hedging tool, has lost its hedging function in a short time because it has become extremely expensive, resulting in a series of collateral effects. Just as Lehman's CDS price soared, investors sold its shares on a large scale, which eventually led to its bankruptcy. The financial crisis mainly made the originally controllable risks beyond people's imagination, and finally the risks crushed the confidence of investors. The financial crisis evolved into a crisis of confidence, and finally spread to every corner of the real economy, forming an economic crisis that swept the world.