The Biology of Risk-On. Decreasing Inflammatory and Stress Responses on a London Trading Floor

Abstract

Human physiological arousal is highly sensitive to information and uncertainty. Little is known, however, about how to measure information in natural settings, nor about which physiological systems respond to it. Financial market prices, and their volatility, present a convenient measure of informational load. Here we report on a study into the physiological response of traders in the City of London during a period of extreme, but declining, volatility. We sampled salivary cortisol, the main stress hormone, and the pro-inflammatory cytokines, IL-1{beta}, IL-6, IL-8, and TNF- three times a day for two weeks. We found that average daily cortisol levels tracked closely an index of equity and bond volatility, as did levels of IL-1{beta}. Within-day cortisol and IL-1{beta} levels also tracked one hour lagged volatility. Interestingly, the cascade of endocrine and immunological changes was initiated by IL-1{beta}, the first responder of the stress and inflammatory responses. Our results have implications for finance because chronic stress and the immune response known as sickness behaviour could have powerful effects on risk-taking and market stability.