Early exercise is when you choose to exercise your stock options before they have vested. This can be a way to minimize your tax liability and increase potential gains depending on the Fair Market Value of your company and your exercise price. Some option holders choose to early exercise so that when the options vest, they already hold the shares. This can be tax advantageous to start the long-term capital gains clock ticking. It's important to point out that not all stock plans or companies offer early exercise.