In a study that I started in 2003 and disseminated in the first half of 2004 and that was published in Management Science in May 2005 (available at I found that stock prices also tend to decrease before the grants.Furthermore, the pre-and post-grant price pattern has intensified over time (see graph below).

option back dating-8

Because the option value is higher if the exercise price is lower, executives prefer to be granted options when the stock price is at its lowest.

Backdating allows executives to choose a past date when the market price was particularly low, thereby inflating the value of the options.

An example illustrates the potential benefit of backdating to the recipient.

The Wall Street Journal (see discussion of article below) pointed out a CEO option grant dated October 1998.

By the end of the 1990s, the aggregate price pattern had become so pronounced that I thought there was more to the story than just grants being timed before corporate insiders predicted stock prices to increase.

This made me think about the possibility that some of the grants had been backdated.

Awarding employees with stock options those are dated prior to the actual grant date.

The date chosen could be one when the company’s stock was at a low, so the options can be in-the-money at the time of granting itself.

Backdating does not violate shareholder-approved option plans.