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Share Buybacks Explained: How They Work, Why Companies Do Them, and Whether They Actually Help You
A share buyback (or stock repurchase) is when a company uses its cash to buy its own shares from the market and usually cancels them. With fewer shares outstanding, each remaining share owns a bigger slice of the company's profits, so earnings per share (EPS) rise even if total profit doesn't. Buybacks are the main alternative to dividends for returning cash to shareholders. They're more flexible for companies and can be more tax-efficient for investors, because you only pay tax when you sell. S&P 500 companies spent a record of more than $1 trillion on buybacks over the 12 months to September 2025, according to S&P Dow Jones Indices. Since 2023, US companies have paid a 1% excise tax on net repurchases. Buybacks help shareholders when the stock is bought at a reasonable price with genuinely spare cash; they destroy value when companies overpay, borrow heavily to fund them, or use them mainly to offset stock handed out to employees. In October 2026, GM approved a new $20 billion buyback after cutting its share count by about 6% this year.
What is a share buyback?
A share buyback, also called a stock repurchase, is when a company uses its own cash to buy back its shares, usually on the open market, and then cancels them.
It's like a pizza being cut into fewer slices. The pizza (the company's profits) is the same size, but each slice (each share) is bigger.
How buybacks work: a simple example
| Before buyback | After buying back 10% of shares | |
|---|---|---|
| Net profit | $1,000 million | $1,000 million |
| Shares outstanding | 100 million | 90 million |
| Earnings per share (EPS) | $10.00 | $11.11 |
| Your shares | 1,000 | 1,000 |
| Your share of the company | 0.0010% | 0.0011% |
You didn't do anything, but you now own about 11% more of the company's profits per share. That's why buybacks are often described as a way to return cash to shareholders who don't sell.
There's a catch. The company spent cash to buy those shares, so it's now holding less money. Whether shareholders gain in the long run depends on the price paid.
A real example: GM
On October 20, 2026, General Motors approved a new $20 billion buyback after finishing a $6 billion program announced in January. It had already reduced its share count from 904 million at the end of 2025 to 849 million by September 30, about 6% fewer shares.
That helps explain how GM's adjusted earnings per share rose 32% in the third quarter while revenue rose only about 3% (our GM report). Part of the EPS growth came from higher profit, and part from fewer shares.
Insurer Travelers is another example. It bought back $1.5 billion of stock last quarter and says it has retired 12% of its shares since the start of 2025 (Travelers report).
How big are buybacks?
Very big. According to S&P Dow Jones Indices:
- S&P 500 companies bought back a record $293.5 billion in Q1 2025.
- Buybacks over the 12 months to September 2025 reached a record of more than $1 trillion.
- Companies signalled plans to spend even more in 2026.
The biggest buyers are usually large, profitable technology companies, banks and energy companies with more cash than they can reinvest.
Why companies buy back stock
- To return spare cash when they can't find enough good projects to invest in.
- To signal confidence that the stock is undervalued.
- To offset dilution from stock options and shares given to employees.
- Flexibility. Unlike dividends, buybacks can be slowed or paused without a big negative signal.
- To boost EPS, which some executive pay packages are linked to. Critics say this creates the wrong incentives.
Buybacks vs dividends
| Dividends | Buybacks | |
|---|---|---|
| What you get | Cash in your account | A bigger share of the company |
| Taxes (taxable account) | Taxed when paid | No tax until you sell |
| Company flexibility | Low: cutting a dividend is a bad signal | High: can scale up or down |
| Signal | Long-term commitment | Often opportunistic |
| Best for | Investors who want income | Investors who want growth and tax deferral |
In a tax-sheltered account like an IRA, 401(k), TFSA or RRSP, the tax difference mostly disappears. Learn more in What Is a Dividend?
The rules and the tax
- SEC Rule 10b-18 (adopted in 1982) gives companies a "safe harbor" from manipulation claims if they follow limits on timing, price and volume when buying their own stock.
- Since January 1, 2023, US public companies pay a 1% excise tax on the net value of shares they repurchase each year, under the Inflation Reduction Act.
- Companies must disclose repurchases in their quarterly and annual reports.
When buybacks are good, and when they're bad
Good buybacks:
- Funded by genuinely spare free cash flow.
- Done when the stock is reasonably valued or cheap.
- Actually reduce the share count over time.
- Don't starve the business of needed investment.
Bad buybacks:
- Funded with heavy borrowing, weakening the balance sheet.
- Done at peak prices, followed by issuing new shares cheaply in a downturn.
- Mostly offset employee stock awards, so the share count barely falls.
- Used to hit EPS targets tied to executive bonuses.
A quick check: look at diluted shares outstanding in a company's quarterly reports over several years. If it's falling, the buyback is real. If it's flat despite billions spent, much of the money is going to employees, not shareholders.
What it means for you
- If you own an index fund, you already benefit from buybacks across hundreds of companies. They're part of the "total return" of the market.
- If you pick stocks, treat a buyback as one factor, not a reason to buy. Ask what price the company is paying and how it's funding the purchases. Our guides on the P/E ratio and reading an earnings report help.
- Don't confuse EPS growth with business growth. Check whether total profit is rising too.
The bottom line
A share buyback is a company buying itself back from the market. Done with spare cash at a fair price, it quietly increases your ownership and can be more tax-efficient than a dividend. Done with borrowed money at peak prices, it destroys value. The number to watch isn't the size of the buyback; it's whether the share count actually falls, and what the company paid to get there.
This article is educational and not personalized investment advice.
Frequently asked questions
What is a share buyback in simple terms?
A share buyback is when a company spends its own cash to buy back some of its shares, usually on the stock market, and then cancels them. With fewer shares in existence, each remaining shareholder owns a slightly larger piece of the company.
Why do companies buy back their own stock?
To return spare cash to shareholders, to signal that management thinks the stock is undervalued, to offset shares issued to employees as pay, and to raise earnings per share. Buybacks are also more flexible than dividends, because companies can scale them up or down without the stigma of cutting a dividend.
Do buybacks increase the stock price?
Not automatically. A buyback reduces both the company's cash and its share count, so in theory the value per share is unchanged at the moment of purchase. Shareholders benefit over time if the company bought at a price below the stock's true value and if earnings per share keep growing on the smaller share base.
Are buybacks better than dividends?
It depends. Dividends give you cash you can spend or reinvest, but they're taxed when paid in a taxable account. Buybacks don't create a taxable event unless you sell, so they can be more tax-efficient. Dividends signal a long-term commitment; buybacks are more flexible. Many companies use both.
Is there a tax on stock buybacks?
Yes, for US companies. Since January 1, 2023, publicly traded US corporations pay a 1% excise tax on the net value of shares they repurchase in a year, after subtracting new shares issued. Investors themselves pay no tax from a buyback unless they sell shares.
When are buybacks bad for shareholders?
When the company overpays for its own stock, borrows heavily to fund repurchases and weakens its balance sheet, skips investments that would earn more, or mainly uses buybacks to offset dilution from employee stock awards so the share count barely falls. Some companies that bought back heavily before 2008 or 2020 later needed rescues or raised new equity at lower prices.
How do I know if a company is really reducing its share count?
Compare the diluted shares outstanding in its quarterly reports over several years. If the buyback total is large but the share count is flat, much of the buyback is offsetting employee stock grants. GM, for example, cut its shares from 904 million at the end of 2025 to 849 million by September 30, 2026.
Primary sources
- S&P Dow Jones Indices — S&P 500 Q3 2025 buybacks post modest 6.2% gain to $249.0 billion; 2025 anticipates a record $1 trillion (Dec. 18, 2025)
- S&P Dow Jones Indices — S&P 500 Q1 2025 buybacks set quarterly record at $293 billion (June 25, 2025)
- 17 CFR 240.10b-18 — Purchases of certain equity securities by the issuer (Cornell LII)
- 26 U.S. Code § 4501 — Repurchase of corporate stock (Cornell LII)
- General Motors — Q3 2026 earnings release, Form 8-K (SEC)
Data & disclaimer: This article is for educational purposes only and is not financial or investment advice. Figures reflect data available as of Oct 20, 2026, and conditions change — always confirm current pricing, rates and rules with the provider before you act. Written by Elizabeta Dimoska. See our editorial standards and disclosure.
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