Your spouse may be entitled to a portion of your retirement. Any portion of your retirement earned during the marriage (and before your date of divorce) will be considered community property. In a divorce, community property is divided between the spouses, but individual assets are not necessarily shared equally. For example, you could keep your retirement and give more equity in the home to your spouse to accomplish an even division of the property.
To determine the characterization of your current portfolio, you will want to gather information/documentation regarding your stock plan such as contact information for the plan administrator. A full list of recommended materials can be found here.