We followed these 17 traders for 8 consecutive business days, taking saliva samples twice per day, at 11:00 a.m. and 4:00 p.m. (10), times that fell before and after the bulk of the day's trading. At each sampling time, traders recorded their profit and loss (P&L), a number displayed live throughout the day on their computerized risk-management system. At the end of each day, the traders filled out a short questionnaire asking, among other things, about food and drinks recently consumed or medication taken. The questionnaire also asked whether the traders had received any important news from outside work. This question, like the others, was designed to find out whether anything other than trading had affected the subject's endocrine system that day. No subject consumed anything during the study that would interfere with his endocrine system, and none received any important personal news.