Losing the medium-term trend

Looks like the S&P 500 is on track for the first real undercut of its 50-day average in nearly 4 months today. It just *barely* undercut it on January 29, but if we look for at least a 0.25% move below, today would be the first time in 81 days (barring a big late afternoon recovery).

When the index lost its medium-term trend for the first time in nearly 4 months, triggering with 3 weeks of a multi-year high, then it has tended to lead to some further short-term selling pressure. By 2 months later, though, the momentum had mostly returned, with the massive exception of last February.