third parties Read that again. For many years, paying for order flows allowed firms to centralize customers’ orders for another firm to execute. Such allowed smaller firms to use economies of scale of larger firms. By allowing small firms to combine orders with larger firms, it provided better execution quality. Over the years, the decimalization of the trading securities diminished the profitability of trade execution. Such pushed Wall Street toward PFOF as a way to generate revenue and subsidize the move to zero-commissions. The advances in technology and data analysis increased the speed with which information gets sent and received. Over the last decade, Wall Street spent billions to figure out ways to take advantage of the data and