That's not right. You have a larger piece of a smaller pie, but you have the same amount of pie.
Edit: the confusion is you are talking about total market cap while the parent is talking about share price. Total market cap is irrelevant to stockholders. Share price is all that's relevant.
Yes, this was my point. Stock buybacks are value neutral if the market value of the company is correct. Ie. the share price stays the same.
All large stock purchases have the short-run effect of elevating the stock price. It would be shocking if this didn't happen; it is not surprising in the slightest that it does.
Edit: Sorry, I got myself confused and mixed up the total market cap (which should go down) with the share price (which should stay the same, because there are now fewer of them).
Consider a company worth $100 with ten shares of stock with $10 of cash on their balance sheet. Each share is worth $10. They company uses the $10 to buy back one share of stock. The company is now worth $90 and has 9 shares outstanding. Each share is still worth $10.
Of course markets are not perfect, and nobody knows for sure if the market value of the company is fair or not. When a company engages in stock buybacks, it’s essentially saying that it believes its stock to be undervalued, which is why stock buybacks sometimes have the surprising effect of elevating the stock price, at least in the short run. After all, who has better information about the company and its prospects than itself?
But as they say, the market is a voting machine in the short run, but a weighing machine in the long run. If it turns out that the market value of the company is higher than its intrinsic value, then stock buybacks are actually destroying shareholder value. The cash would have been better spent buying shares in an index fund.