Sorry to disagree q8! But companies are only allowed to buyback 10% of the daily volume.......because otherwise they would be influencing the stock price......and that´s SEC law!!!!
Just imagine........a low volume day on a huge float.......and suddenly the company starts buying back and sends the PPS to moon........EASY isn´t it?
So you never ever know when a company is buying back....unless some insider info leaks or a PR comes out saying so!