Market analysts at Wells Fargo look at how the price of oil has impacted the stock market since 1980.
Crude oil plunged 54% in 2014 and the 1st quarter 2015. Since 1980 there have been four other instances when the price of oil has been cut in half, averaging a 63% decline. In each case the S&P 500 has rallied an average of 20% over the 12 months following an oil price bottom. Oil prices rebounded to a much greater degree after the expansionary crashes in 1985-1986 and 1996-1999 (103.5%) than after the recession-era bottoms in 1991 and 2008 (36.4%). Historically the stock market reaction to the fall in oil price "has been able to shrug it off each time – similar to what we’re going through now."