Walter Zimmerman, the top technical analyst at United-ICAP, charted the performance of a $10,000 in 1950 if you sold in May, and then bought back on November 1.
"The other half of the proverb is ‘Buy Back on Saint Crispin’s Day,’" said Zimmerman. "That would be 25th October."
"This advice has shined the brightest in those years with the most extreme bullish sentiment going into May."
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