The part of this article that concerned me is the rapid bid/cancel scheme. Traditionally, the cost of finding out about price elasticity in the market is that

The part of this article that concerned me is the rapid bid/cancel scheme. Traditionally, the cost of finding out about price elasticity in the market is that you have to sell/buy some product and see how the market responds. This kind of rapid bid/cancel would be the equivalent of placing a bid on Ebay to see if your competitor's max auto-bid will top it, then retracting your bid. Do this on a regular basis, and you can figure out exactly how much you'd have to bid to beat out your opponents, without putting a cent at risk. A policy that any order must remain in force for at least one full second (long enough for standard electronic trading services to act on it) would probably limit this behavior.