Discount brokers saw their daily average trade (DART) volume increase slightly in September, though they are still down for the quarter. September is normally a strong month, but uncertainty and an ‘unusually active August’ depressed trade volumes somewhat, say David J. Chiaverini and Richard Fellinger. Discount broker uncertainty in market Based on their channel contacts, the analysts estimate just 2 percent growth in DARTs. “The modest month-over-month increase contrasts with the normal seasonal increase of 9 percent (median over the last 10 years),” they write. “We attribute the tepid trading activity to tougher comps from an unusually active August and…