Tech Leads S&P Above 2,600; Amazon, Other Retail Stocks Gain<br />(Reuters) - Technology stocks led the S&P 500 and Nasdaq to record closing highs on Friday, with the S&P ending above 2,600 points for the first time, while Amazon<br />and retail stocks got a boost from signs of a strong start to the holiday shopping season.<br />Adobe, which measures 80 percent of online transactions at the largest 100 U. S. web retailers,<br />forecast online Black Friday sales of $5 billion, which would be a record high.<br />The stock market had a half session on what is known as Black Friday, the day after the Thanksgiving holiday<br />and the unofficial start of the U. S. holiday shopping season.