"I knew it was an amendment but why was an 13D amendment not filed with the last batch of stocks that pike bought?" Actually there were....remember those "private transactions" where he just swapped shares between his own funds don't count. http://sec.gov/Archives/edgar/data/1201251/000114036110001954/0001140361-10-001954-index.htm "If it does nothing then why does the 4 form not suffice?" Not smart enough for that one.....but the 4 doesn't provide for the filer to indicate his intentions, while the 13D does.