"Buybacks give money to shareholders who sell. Dividends give money to shareholders who don't sell." Interesting to model the effects of that. Buybacks tend t

"Buybacks give money to shareholders who sell. Dividends give money to shareholders who don't sell." Interesting to model the effects of that. Buybacks tend to concentrate ownership among the shareholders that are most optimistic about the company's future. Since the only way to take your cash out is to sell, the most marginally-attached shareholders will sell, leaving only the shareholders who believe the company is worth much more in the future. This could have much more dramatic effects on stock price than is financially rational, because it decreases the liquidity of the stock and decreases the pool of people who might sell in response to rational analysis (because they already sold, and their stock is now retained by the corporation itself, which is not a disinterested party). It also increases the ease of corporate governance but decreases the efficiency of it. Buybacks flush out the most marginally-attached shareholders, those most pessimistic about the company, and so they give company management a shareholder population that is largely on-board with company strategy and not inclined to exit, because they've already had plenty of chances to exit. But the whole point of markets is to aggregate the opinions of many independent parties and avoid groupthink. If the shareholder base is self-selecting, it's particularly vulnerable to groupthink, and by definition has a higher opinion of the company's prospects than the market as a whole. Multiplied across thousands of stocks, that probably makes the market less efficient than without buybacks, also congruent with the declining liquidity. We don't observe declining liquidity, but much of that is because of market makers and passive investors that don't have an opinion or vested interest in the future of the stock itself.