Clean water and electric power are essential for modern life. In the same way, the financial infrastructure is the foundation for our economic system. Most of us take all three of these, water, electricity and finance, for granted, assuming they will operate through thick and thin.

As engineers know well, a system’s resilience depends critically on the design of its infrastructure. Recently, we discussed the chaos created by the October 1987 stock market crash, noting the problems associated with the mechanisms for trading and clearing of derivatives. Here, we take off where that discussion left off and elaborate on the challenge of designing a safe derivatives trading system―safe, that is, in the sense that it does not contribute to systemic risk.

Today’s infrastructure is significantly different from that of 1987. In the aftermath of the 2007-09 financial crisis, authorities in the advanced economies committed to overhaul over-the-counter (OTC) derivatives markets. The goal is to replace bilateral OTC trading with a central clearing party (CCP) that is the buyer to every seller and the seller to every buyer....