CoinDesk reported:
It’s important to note that while August typically experiences lower volatility, it’s not a hard-and-fast rule, as reduced trading activity and lower liquidity can magnify significant moves when they do occur. This seasonal illiquidity doesn’t afford market participants much in the way of market depth that can absorb news shocks or reprice major events. And in the rare event they do occur during the illiquid summer months, they can be meaningful (see the Quant Crisis of August 2007, the U.S. credit rating downgrade in August 2011, the Chinese yuan devaluation in August 2015), keeping traders glued to their laptops and Wi-Fi or forcing them to end their vacations prematurely.