Eliminating all biases when investing is nearly impossible. Financial markets are a prime example of the way human biases can manifest at either end of a spectrum of emotions: This is the core of behavioral finance, where the study of economics and psychology intersect.

Issuance of securities backed by riskier US mortgages roughly doubled in the first quarter from a year earlier, as investors lapped up assets blamed for bringing the global financial system to the brink of collapse a decade ago.