The S&P 500 snapped a seven-session winning streak, as investors worried about the prospects for a broad coronavirus relief package. The index had opened modestly higher and flirted with record levels for most of the session, before pulling back in the final hour of trading. It ended the day down 26.78 points, or 0.8%, at 3333.69. The S&P is off just 1.5% from February’s high. The...