Gap and crap
The S&P 500 fund, SPY, gapped up to a multi-year high then reversed to close below the prior day's low. This is typically considered a key reversal day, though we've seen in the past that "key" is much too strong of a word. Of the 21 other times that SPY has suffered a similar reversal, it managed to rebound over the next three days 43% of the time, averaging -0.2%, so some follow-through weakness in the very short-term. But by a week later, it was higher 76% of the time, with no consistent sign of lingering weakness despite the ugly-looking bar on the charts.