Right now ahead of Halloween, the real suspense might be in ETF investing strategies. With markets seesawing between hopes for rate cuts and the resilience of earnings, investors are dusting off one of Wall Street’s spooky old sayings:  Sell in May and go away.The so-called Halloween Effect, a pattern where stocks outperform between November and April, might sound like folklore. But the data has teeth. Yardeni Research’s historical analysis of the S&P 500 shows that from 1928 to 2025, returns averaged 5.2% ...