5 things that make this stock-market selloff truly unusual - MarketWatch
1. U.S. stocks faced significant drops, drawing historical comparisons to 1987 and 2008. 2. Earnings forecasts for S&P 500 firms have remained steady despite market volatility. 3. Passive index investing's growth may be accelerating selloff speed. 4. Recent selloffs are largely policy-driven rather than market-driven events. 5. S&P 500 futures have seen unprecedented declines, resembling past major market crashes.