Tuesday’s rally in U.S. stocks was so broad and so extensive, it brought something unique that often triggers continued rallies, Bank of America technical research strategist Stephen Suttmeier wrote to clients Wednesday. Almost 94% of all the stocks traded on the New York Stock Exchange rose in price Tuesday, and almost 92% of all the shares that changed hands traded on an uptick, a rarely seen wave that resulted in “a 90% up day,” BofA noted. “We view this bullish breadth day as a sign that the 4Q rally for U.S. equities from … late October can continue,” Suttmeier wrote. “This comes after a bullish NYSE breadth thrust signal ” on Nov. 3. BofA looked at 86 prior incidents of such broad-based advances in stocks and checked how stocks performed subsequently. The S & P 500 median return the next day was a muted -0.05%. But 10 days later, the median return was 1.44%; 20 days later the index was usually ahead a median 2.24%; and after 30 days it was a median 3.28% higher. After 65 days, median returns were better still, with the benchmark index surging another 6.21% from that original “90% up” day. One caveat: nothing’s a sure thing in the market, and returns can be scattered. One time, the maximum return after 65 days was 30.51%, and the maximum loss 65 days after such a “90% up day” was 16%.