What distinguishes stock insurance companies regarding policy dividends?

Stock insurance companies are distinct in that they operate with a focus on generating profits for their shareholders, rather than primarily for their policyholders. A key characteristic of stock insurance companies is that policyholders do not receive dividends based on the company's profit performance; instead, they may receive dividends from mutual insurance companies, which are owned by policyholders.

In the context of dividends, stock insurance companies typically issue non-participating policies. These policies do not allow policyholders to share in the company’s profits through dividends. Policyholders of stock companies therefore do not have the potential to receive dividend payments linked to the company's success, unlike participating mutual companies where dividends are distributed if the company performs well financially.

The other options highlight characteristics related to mutual insurance companies or misunderstand aspects of stock companies. Therefore, the specific trait that differentiates stock insurance companies concerning policy dividends is that they issue only non-participating policies, leaving shareholders to benefit from the company's profits.