Stock-market indicator with a near-perfect track record is flashing a ‘buy’ signal. Here are the most volatile days for stocks before the election, according to the options market. Dow Jones Industrial Average futures are dipping 0.1%.

The chipmaker ended the day up by about 4%, jumping on news that its CEO Jensen Huang was done selling stock for now. Under a predetermined trading plan, the executive was authorized to sell 6 million Nvidia shares through early next year — but he just met that threshold, Barron's first reported.