What type of report must be filed within 15 days of a significant event such as a leadership change or bankruptcy?

The required report to be filed within 15 days of a significant event, such as a leadership change or bankruptcy, is the Form 8-K Current Report. This form is specifically designed to disclose important events that may be of interest to shareholders and the public, ensuring that timely information is available regarding any material changes that could affect the company's financial health or operations.

The purpose of Form 8-K is to provide transparency, allowing investors to make informed decisions based on the latest developments within a company. Unlike the Form 10-K, which is an annual report detailing a company's overall financial performance and operations, or the Form 10-Q, which is a quarterly report summarizing financial results, the 8-K is focused on current and significant events. Proxy statements also serve a different purpose by facilitating communication with shareholders regarding upcoming votes on corporate matters, rather than informing them about recent significant changes. Thus, the nature and timing of Form 8-K align perfectly with the necessity to report impactful corporate events efficiently.