NEW YORK — Wall Street resumed its slide Wednesday as unease about the wilting mortgage market and the broader economy triggered selling ahead of the unofficial start of the holiday shopping season. The Standard & Poor's 500 index and the Dow Jones industrial average each fell by more than 1.5 percent, with the Dow giving up more than 210 points.

The decline in the S&P 500 left the index in negative territory for the year. Many investments such as mutual funds either track or are measured against the S&P.

Wednesday marked the eighth time in the last 11 sessions that stocks have declined — forgoing the boost seen in recent years during Thanksgiving week, which is capped by the retail bonanza Black Friday.