Not all insurance companies offer the same products or cater to the same customer base. Among the largest categories of insurance companies are accident and health insurers; property and casualty insurers; and financial guarantors. The most common types of personal insurance policies are auto, health, homeowners, and life. Most individuals in the United States have at least one of these types of insurance, and car insurance is required by law. A stock insurance company is a corporation owned by its stockholders or shareholders, and its objective is to make a profit for them. Policyholders do not directly share in the profits or losses of the company. To operate as a stock corporation, an insurer must have a minimum of capital and surplus on hand before receiving approval from state regulators. Other requirements must also be met if the company’s shares are publicly traded. Some well-known American stock insurers include Allstate, MetLife, and Prudential.