What is ' the concept was heavily marketed'? As one example of what can happen under forced sales, Buffett reviewed October 19, 1987: The infamous Black Monday when the Dow Jones Average dropped 23% in a single day. It was driven by portfolio insurance, which was a joke. It was a bunch of stop/loss orders, but done automatically, and the concept was heavily marketed. People paid a lot of money for people to teach them how to put in a stop/loss order.