This paper documents that complex financial innovations like collateralized debt obligations (CDOs) enabled informed parties in the commercial mortgage-backed securitization pipeline to reduce their skin-in-the-game in a way not observable to other market participants. This reduction in first-loss security retention significantly impacted the probability that more senior tranches ultimately defaulted. We show that this performance is entirely driven by the amount of first-loss sold to (affiliated) CDOs within 12 months of the commercial mortgage-backed securities (CMBS) deal. Our result is robust to using the differential access of first-loss investors to CDO funding as an instrument to identify exogenous variations in the retention of first-loss securities.