Stock Market's Big Moves Happen While Traders Sleep
• The S&P 500 has realized most of its gains over the last 30 years when the market is closed, according to data from Bespoke Investment Group.
• This data shows that the events most important to stock prices tend to happen outside of market hours, like earnings reports and economic data releases.
• The Federal Reserve's monetary policy announcements are an outlier that do move markets during trading hours.
• Recent stock market volatility on days like Wednesday is often blamed on obscure factors, but earnings still drive prices over the long run.
• In the end, this data supports the views that markets are efficient but also resemble a random walk day-to-day.