HYG was the first mover in the high-yield corporate bond market. For many years its been one of the largest and most liquid junk bond ETFs, along with archrival JNK. Its core exposure through the iBoxx index it tracks is solid, covering the most liquid corner of the junk bond market. HYG replicates much of the overall junk bond market, but often with shorter maturity, less interest-rate sensitivity, and also less yield. HYG tends to tracking its index more closely than most. However, direct comparisons are difficult, as HYGs underlying index factors in transaction costs, while others, following industry convention, do not. In sum, HYG is an anchor tenant in the ETF bond market.