Legal question: Insider trading claims might be difficult since you can claim the vulnerabilities were public knowledge waiting to be discovered, but... Can you trade on knowing the security disclosure timeline prior to your publication of the vulnerability? That would seem to be insider knowledge until AMD authorizes publication. E.g. I've got knowledge that AMD likely wouldn't be able to fix the flaws prior to my d…
Imagine someone buying stock and then saying the company is good. Not very controversial is it. Warren Buffet does it. Shorting stock and saying the company is bad is just the flip side of it.
In fact, there are equity research companies that do specifically that (e.g. Muddy Waters). Whether that research holds water or not is for the market to determine (AMD is up on the day).