Snowballing effect…

Drawing particular attention were stocks that posted far bigger losses than the broad market. At least eight in the Standard & Poor’s 1500-stock index fell to a price of one cent per share—essentially a 100% decline. Among them were Boston Beer, Exelon and Accenture.

With Accenture, for example, 20,365 shares changed hands at around $39.98 during the minute of 2:46 p.m., then another 68,516 shares were traded at $38 per share during the minute of 2:47. But then in the 2:49 p.m. minute, 66,277 shares traded at one cent. By 2:50 p.m., the stock was back up to $39.51.

Several more stocks dropped by more than 60%. Among the stocks in the S&P 1500, 15 stocks fell more than 50% from their day’s high to their low and 61 stocks fell more than 20%.