For several years, the Wall Street wizards who built a faster, more fragmented stock market justified their creation by pointing to the benefits it yielded for investors in the form of lower trading costs. But as the speed and complexity of the markets have continued to change at a rapid pace — with trade times now measured in millionths of a second — a growing number of studies and market participants suggest that those benefits to investors have stalled or even started to reverse. Research from the broker Abel/Noser indicates that the total cost for an investor to get into and out of a single share of stock fell by ... (full story)