(Bloomberg) -- Credit Suisse Group AG must face allegations that it engineered a complex fraud to sink an investment vehicle and profit on investors’ losses, after an appeals court revived the claims. The lawsuit, filed in 2018, claimed investors lost $1.8 billion in the Feb. 5, 2018, collapse of the market for VelocityShares Daily Inverse VIX Short Term Exchange Traded Notes, known as “XIV Notes,” a derivative investment that increased in value when the stock market was calm and decreased when it was volatile.