Fischer Black Would See Bubbles as Traps for Traders

Cliff Asness, co-founder of AQR Capital Management, made the news recently with the provocative claim that financial markets are getting less efficient. I worked at AQR for 10 years, but long before that I spent nearly two decades as the only mentee the renowned economist Fischer Black ever had. Fischer had a very different view of market efficiency and would, I think, have reached a different conclusion from Cliff’s data.