Weekly $SOX chart with MACD crossings: Gerald APPEL recommends an 8-17-9 MACD to generate buy signals, and a 12-25-9 MACD to confirm a sell signal for a stock, which has had a strong bullish move <img src=http://stockcharts.com/c-sc/sc?s=$SOX&p=W&yr=3&mn=6&dy=0&i=p50225031619&r=991>