Earnings per share, or EPS, is a company's profit measured against a single share: net income divided by the number of shares. A share buyback reduces that number. The profit does not change, but it is now split among fewer shares, and EPS rises. That is an arithmetical fact. Whether it creates value, or merely shifts it, is another matter entirely.
1 What are we talking about?
Two notions, one division.
Definition
The profit, per share
Earnings per share measures what a single share earns: the company's net income is divided by the number of shares outstanding. A share buyback is the mirror image of an issue: the company uses its cash to buy back its own shares on the market, then most often cancels them. The number of shares falls. Because earnings have not budged, each remaining share now represents a larger slice of the same profit.
2 The mechanism
One example explains it all.
Splitting the same pie into fewer slices
①
Before. Earnings of 100, spread over 100 shares: EPS is 1.00.
②
The buyback. The company buys back 5% of the shares; 95 remain. Earnings stay at 100.
③
After. EPS rises to 1.053, roughly +5.3%. Not one extra sale, not one extra dollar of profit. The buyback is said to be "accretive".
The rule of arithmetic
A buyback lifts EPS on one simple condition: that the share's accounting yield (earnings relative to the price) exceeds the after-tax interest rate at which the company funds the operation. It is "purely arithmetical", as the Vernimmen textbook notes: it depends only on the price/earnings ratio and the rate. And it still says nothing about the value created.
3 Accretive vs value
Two words not to be confused.
The misunderstanding
Lifting EPS is not creating value
An "accretive" buyback raises EPS, but it does not create wealth in itself. The consensus, from McKinsey to Aswath Damodaran, is that a buyback returns cash: the price/earnings ratio adjusts downward to match, so that the share price, in theory, does not move. Value comes only from the fundamentals: more sales, better margins. The buyback merely redistributes the same pie among fewer guests.
The only real division
There is one case where a buyback creates value, and one where it destroys it. If it buys back undervalued shares, the company enriches the shareholders who stay at the expense of those who sell. If it buys back overvalued shares, the reverse holds: wealth flows from those who stay to those who leave. Everything therefore depends on the price paid, not on the accretive effect.
4 Good or bad buyback
The same operation, two faces.
✓
The good buyback. At a fair price, with cash that has no better use, and without cutting research or investment: it intelligently returns what the company cannot make grow.
✗
The bad buyback. At the top (buying dear), on credit (weakening the balance sheet), or at the expense of the future (cutting R&D or wages to flatter a ratio).
!
The reading trap. Part of EPS "growth" can be financial in origin, not operational. Telling the two apart is what matters most.
5 Takeaways
To remember.
✓
EPS = net income ÷ number of shares. Fewer shares, higher EPS, with earnings unchanged.
✓
An "accretive" buyback lifts EPS, but does not create value by itself.
✓
It creates or destroys value depending on whether the share is bought back below or above its worth.
This notion sheds light on an analysis
First published: 21 June 2026