As Jeff Kleintop of LPL Financial writes, the average holding period of a stock has fallen from eight years in the 1960s to around five days today.

Much of this is due to the advent of ETFs and high-frequency trading.  But there's little doubt that the average investor is also holding stocks for much shorter periods.

And that comes with consequences.

Here's a chart and commentary from Kleintop's latest Weekly Market Commentary:

One of the consequences of such a short investment time horizon is that investors have begun to fear short-term market events and volatility as much or more than the factors that shape prospects for long-term economic and profit growth that drive stocks over the longer term.