Anon is very often Mutual Funds, Pension Funds, Hedge Funds Venture Capital types and Banks or other Institutions who trade on their own account or for other large Investor types who want to be difficult for the General Market Watchers to track. Makes their doing their business a little more secure as they often get targeted by their rivals and those seeking to ride Coat Tails, etc..

All this also gives those seeking to try some Manipulation a chance to do so before others catch on, etc..

Old Joe