Blue-chip bank stock JPMorgan Chase (JPM) is nursing an 8% deficit in September, cooling off from its Aug. 30 all-time high of $225.48. Last seen lower today to trade at$206.99, it might be time to buy the dip, if past is precedent, as this pullback has JPM encountering a historically bullish trendline.The trendline in question is the shares’ 100-day moving average and per Schaeffer's Senior Quantitative Analyst Rocky White, JPM has run into this trendline seven times in the last three years. For the purpo ...