> The D-Limit product uses data from exchanges to predict when the NBBO is "likely to change in the next two milliseconds," IEX says. If it predicts a bid for a stock will move lower for someone posting a bid, or higher for someone posting an offer, IEX will move the buy price a bit lower than the NBBO and the sell order a bit higher than the NBBO. These times average just five to 10 seconds of the entire trading day but make an outsized impact because a large volume of orders trading against displayed quotes come in these moments, IEX says.