Stock Buyback, Purchasing your own Stock

Has anyone found purchasing your own stock to be effective?

I played a bit trying to see if I could bid my stock up the point that no one could afford to buy it but it seemed to help my enemies more than myself. When you buyback stock it takes away from the finite amount of purchases that are able to be done in a game thereby enabling other players to arrive at the "purchase entire company" point in a faster time frame. Buying my own stock just meant that the players were able to buy me out and I lose at a quicker pace.