Does the company buy back stock opportunistically?

EPS is the most important measure in determining what a share of stock in the business is worth.
If the stock is undervalued, these stock repurchases can add materially to the value of the company
Management might decide to buy back stocks one time or predetermined amounts each year

There are a couple of common motivations behind stock repurchases
Management may believe the stock is undervalued so it takes advantage of the opportunity to potentially add value

Management may want to offset dilution from issuing stock options

Companies such as Western Union money transfer which has a strong cash flow began repurchasing 1billion $ worth of stock
each year.

Auto Zone’s EPS grew at a rate of 16% from 2002 to 2010 while its net income grew at a rate of 7% over the same period.
The main reason for the difference was due to the share repurchases which reduced the number of outstanding shares
Had AutoZone not repurchased stock, the EPS would only grow by 7% which would have resulted in lower stock price

Similarly when a company issues new shares (Stock options,..), it increases the number of shares outstanding
Although the growth rate of GM was better than that of Western union money transfer, EPS of GM was lower than Western union money transfer