Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Insider trading in another company?
This information is clearly "material" (large impact) and "non-public" according to the statement of the problem.  Also, decisions like United States v. Carpenter make it clear that you do not need to be a member of the company to do illegal insider trading on its stock. Importantly though, stackexchange is not a place for legal advice and this answer should not be construed as such.  Legal/compliance at Company A would be a good place to start asking questions.