One sentiment indicator is flashing "yes."
Is relentless optimism the same thing as irrational exuberance? You have to ask yourself that question when you regard equity market charts nowadays. The S&P 500 has been on a tear recently, fueled by short-covering rallies in early February and fresh buying through mid-month.
You might have been able to forecast this rally a while ago if you kept track of the SPY-OEF spread. The SPDR S&P 500 Trust ETF ([[SPY]]) is a tradable proxy for the U.S. market's blue chip benchmark. The iShares S&P 100 ETF ([[OEF]]) tracks