Another idea (sans - or in addition to a tax) to improve the signal / noise ratio of the markets: mandate that all B/Os put out there have a TTL of 5 seconds or

Another idea (sans - or in addition to a tax) to improve the signal / noise ratio of the markets: mandate that all B/Os put out there have a TTL of 5 seconds or until they are hit. So if you Bid at X, you can't pull that bid 10 microseconds later. You can't quote stuff / probe with orders you never expect to get hit. You can't create the appearance of 'market depth' where none exists at all.