Are there better times to invest in stocks?

55% of Americans are reported to be invested in the stock market according to robo.1db.com/Gallup. The S&P chart shows the stock market advancement and daily volatility. Volatility has averaged .989% each trading session from its intraday high and low points. The question, has the market presented optimal times to invest over this bull run or is it all really just random? 1db.com #RoboAdvisor 1db.com