Tesla Inc.’s price cuts have led Wall Street to lower estimates for the electric-vehicle maker’s profit, and to question its prospects. On Wednesday, investors will have a chance to see just how much the cuts have mattered in a larger context for Tesla TSLA, -1.59%, which is scheduled to report fourth-quarter earnings then. “With the increased competition around the world, Tesla’s profit margins are definitely under threat,” said Sam Fiorani, vice president of global vehicle forecasting at AutoForecast Solu ...