You are a salestrader on the high-yield bond desk. A client that you have covered for many years has recently moved from a mutual fund to a small startup hedge fund. For the first time in his career he is allowed to take short positions in addition to long positions. He believes the market is underpricing the risk of defaults in the auto parts sector. He asks you to explain his options for expressing this view. Can you explain the two main types of trades he could establish that are related to chemical sector bonds, including the mechanics and pros/cons of each?