Guide to Stock Buybacks
Understanding share repurchases, their strategic uses, and market impact
What a Buyback Is and How It Works
A share repurchase (buyback) is when a company acquires its own outstanding shares, typically on the open market or via a tender (including Dutch auctions), reducing free float and—other things equal—raising earnings per share (EPS) by lowering the denominator.
Regulatory Framework
In the U.S., open-market repurchases operate under the SEC's Rule 10b-18 "safe harbor," which outlines non-manipulative conditions on manner, timing, price, and volume:
- •One broker per day
- •Prices no higher than the highest independent bid or last transaction
- •Volume cap of 25% of average daily volume
These conditions are not mandatory but provide a safe harbor from manipulation liability if followed.
Flexibility and Completion Rates
Open-market programs are flexible: unlike fixed-size tender offers, firms do not pre-commit to complete the entire announced amount. In a classic study of 450 programs (1981–1990), firms ultimately acquired ~74–82% of announced shares within three years—evidence of partial adjustment and managerial discretion.
A Brief History
Before 1982, open-market repurchases were often treated as potentially manipulative. The introduction of Rule 10b-18 in 1982 formalized a safe harbor, after which repurchases expanded markedly in the U.S. payout landscape.
Structural Shift in Corporate Payouts
Multiple large-sample studies through the 1990s–2000s show this structural shift. Grullon and Michaely (2002) conclude that firms increasingly financed repurchases with funds that otherwise might have gone to dividends, making buybacks the preferred form of initiating payouts by the late 1990s.
Skinner (2008) similarly shows the rise of three groups—"dividend-and-repurchase," "regular-repurchase," and "occasional-repurchase" firms—while "dividend-only" payers largely faded.
Scale of Activity
Source: S&P Dow Jones Indices (Methodology and totals are specific to the S&P 500 cohort)
Why Companies Use Buybacks (vs. Dividends)
Open-market repurchases are voluntary and non-sticky: managers can scale them up or down without the reputational penalty associated with cutting dividends. Survey evidence from Brav, Graham, Harvey, and Michaely (2005) shows managers strongly avoid dividend cuts and cite flexibility as a key advantage of repurchases.
Key Advantages
- ✓No commitment to maintain future levels
- ✓Can be paused or reduced without market penalty
- ✓Allows response to changing business conditions
How Repurchases Affect Investors and Firms
Share Count and EPS
By reducing shares outstanding, repurchases raise EPS ceteris paribus. The EPS-threshold evidence shows some firms time repurchases to achieve reporting objectives, with documented real-effects trade-offs.
Stock Price Reactions
Classic empirical work finds that repurchases tend to be announced after weak prior performance and in contexts consistent with undervaluation; announcement effects and post-event performance have been widely examined. (For instance, Stephens & Weisbach observe increased repurchasing following price declines.)
Payout Mix and Investor Clientele
With dividends perceived as a commitment and repurchases as discretionary, the mix influences which investors a firm appeals to. Manager surveys show that tax considerations are secondary to flexibility and signaling, though tax remains a factor in overall payout design.
Market-Wide Scale
At the index level, buybacks have represented a very large cash return channel in recent years. S&P DJI documents $922.7B (2022) and $942.5B (2024) in S&P 500 repurchases; Q1 2025 set a quarterly record ($293.5B). (These figures are specific to S&P 500 constituents and reflect S&P's methodology.)
Why Buybacks (Sometimes) Instead of Dividends
Avoiding Dividend-Cut Stigma
Managers prefer the option to pause/slow repurchases if conditions change, whereas cutting a cash dividend is strongly avoided. Surveyed managers explicitly cite this.
Responding to Transitory Cash Flows
If excess cash is viewed as temporary, repurchases can distribute it without creating a perceived obligation to maintain a higher dividend level. Empirical work aligns with this substitution/flexibility logic.
Perceived Undervaluation
Repurchases can signal management's view that shares are undervalued and can be used (selectively) to adjust leverage and optimize capital structure.
Compensation Management
Buybacks can offset dilution from employee equity compensation—one of the operational motives documented across the literature.
Tax Considerations
Historically, repurchases could offer tax advantages relative to dividends for some shareholders. The post-2022 U.S. 1% excise tax narrows (but does not eliminate) that advantage at the entity level.
Implementation Forms and Regulatory Frame
Open-Market Repurchases (OMRs)
Dominant in the U.S., conducted within 10b-18's safe-harbor conditions. Completion is not required; actual take-up averages well below 100% of announced targets.
Tender Offers (Including Dutch Auctions)
Fixed-size repurchases at a premium within a window; less flexible but provide immediacy and commitment. (Background and contrasts appear throughout the OMR literature.)
Disclosure Requirements
Amendments associated with 10b-18 increased periodic reporting of repurchases in Forms 10-Q and 10-K, enhancing transparency on amounts and timing.
Economic Effects—What the Research Says
Substitution and Payout Policy Evolution
The weight of evidence shows repurchases rising as a key payout channel, substituting for dividend increases and becoming the preferred initiation method among younger firms.
This represents a fundamental shift in how corporations distribute cash to shareholders, with buybacks now dominating the payout landscape.
The Current Tax Environment
The U.S. Inflation Reduction Act of 2022 created a 1% excise tax, effective for repurchases after December 31, 2022, levied on the net value of repurchases (with specific adjustments).
Key Tax Details
- Rate: 1% excise tax on net repurchases
- Effective Date: Repurchases after December 31, 2022
- Reporting: Treasury/IRS guidance clarifies reporting mechanics (Form 720/7208)
- Impact: This entity-level tax reduces the historical tax preference for buybacks over dividends but is modest in magnitude
Conclusion
Stock buybacks have evolved from a once-suspect practice into a central pillar of U.S. payout policy since the 1980s. Their attraction is straightforward: flexibility, the ability to target perceived undervaluation, and an avenue to manage capital structure and dilution—without the sticky commitment of dividends.
Important Considerations
The literature also cautions that, around short-term earnings thresholds, some buybacks crowd out investment and employment. Recent U.S. policy—the 1% excise tax effective after Dec. 31, 2022—tilts the calculus slightly back toward dividends at the margin but leaves intact the broader strategic functions that have made buybacks a dominant payout mechanism.
Important Disclaimer
This content is for educational and informational purposes only and does not constitute financial, investment, tax, or legal advice. The author is not a registered investment advisor, certified financial planner, or certified public accountant. Always consult with qualified professionals before making any financial decisions. Past performance does not guarantee future results. Investing involves risk, including potential loss of principal.
The information provided here is based on the author's opinions and experience. Your financial situation is unique, and you should consider your own circumstances before making any financial decisions.
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