Stocks advanced Friday, but the gains came in declining volume. The Nasdaq added 1%, while the S&P 500 and the Dow Jones industrial average rose 1.3% and 1.6%, respectively. The IBD 50 checked in with a 1.4% pop. Volume fell across the board. The gains in the indexes were primarily the result of a strong start. The Nasdaq was up 1.9% at midday and then gave back a chunk of the advance as it met resistance near the 200-day moving average.