Comment by nyeah

There is supply and demand to consider. Buybacks create a tendency toward higher share prices, but only while they continue. That demand cuts off when the buybacks stop.

If the buybacks are at a discount to whatever the stock turns out to have been worth at the time, then that benefits all the shareholders. That can be a great use of money for all shareholders.

But buybacks at inflated prices benefit only exiting shareholders. Exiting shareholders tend to include hired management. Of course nobody really knows the valuation that well, so obviously there's a guessing game.

This is pretty hard to argue against for anybody who agrees that valuation is a thing at all.