Two professors calculated real stock prices (adjusted for changes in the CPI) back to 1857 and concluded that [18] inflation-adjusted stock prices were approximately equal to nominal stock prices in 1864–1865, were greater than nominal prices through 1918, tracked them rather closely … following World War I and were nearly equal to them throughout the World War II period. Since the end of World War II, however, the nominal and real stock price series have begun to diverge, with the real price moving further below the nominal price.

What does this conclusion, by itself, tell us about stock prices and consumer prices during these years?