How It Works
For example, let's assume that John Doe is the CEO of Company XYZ. When he was hired, the Company XYZ board of directors offered John an attractive salary as well as an annual grant of 1,000 Company XYZ stock options. Those options give John the right but not the obligation to purchase 1,000 shares of Company XYZ stock at the market price on the date of the grant. The board formally grants the stock options to John every year at its January board meeting.
Typically, the grant date of the stock options is the same as the date of the board meeting. This is important to note, because the grant date is what determines the exercise price on the options. For instance, if the board meeting is on January 3, 2012, and Company XYZ stock closes at $45 per share that day, then the exercise price of John's 2012 stock option grant is $45 per share. That is, he has the right but not the obligation to purchase 1,000 shares of Company XYZ stock for $45 per share.
If, however, Company XYZ decides to backdate the options, it could change the paperwork to state that it actually granted those stock options to John on, say, June 15, 2008, when the stock was only trading at $15 per share. This would mean that John's 2012 stock option grant would have an exercise price of $15 per share instead of $45 per share.
Let's say that John now decides to exercise his stock options. On the day he decides to exercise his options, Company XYZ shares are trading at $50. Under normal circumstances, he pays the $45 per share exercise price and can turn around and sell those shares on the exchange for $50 each, netting a profit of $5 per share, or $5,000 total.
But if John's options are backdated, then his exercise price is only $15 per share. He pays the $15 per share exercise price and can turn around and sell those shares on the exchange for $50 each, netting a profit of $35 per share, or $35,000.