There are many different choices for bug bounty programs to participate in, but most boil down to two types: third-party marketplaces and company-sponsored programs.
An Overview of Bug Bounty Communities – Where to Start Your Search
Third-Party Marketplaces
Marketplaces are sites that match companies and researchers. They standardize the submission process, rules of engagement disclosure, and other documentation, while providing forums, teaching blogs, and other services to the community. Marketplaces are good sources of technical information and the metrics they typically collect – related to things such as a company's response time and average payout – can help you decide where to direct your efforts...