Stocks are stuck in a range defined by a shrinking numerator (lower economic growth and lower expected profit growth) as well as a shrinking denominator (lower bond yields). The 10-year US Treasury yield has fallen from 3.23% in early October 2015 to 2.62% today, a plunge of 60 basis points, while the German Bund yield has fallen almost 50 basis points, from +0.5% to -0.05%.

The central banks put their fingers into the electrical socket in early 2018, and back-pedaled vigorously at the end of 2018, assuring the markets that they would do nothing at all during the course of the year.

Read more: Wile E Coyote and market volatility