Investigations/actions can take months or years depending on the amount of digging they have to do. If they go after a company, they want to build a strong case. I've seen them take action 1 or 2 years after the alleged misconduct occurred b/c they tracked down every transaction by the companies plus 3rd parties over a period of years.
It doesn't matter if it is an SEC-reporting company, or a pink sheet stock either. If the SEC believes a company violated federal law, the SEC will act.
My posts are solely my opinion unless presented with (or directed to) factual information. All investors are strongly encouraged by myself to do their own due diligence before making an investment decision.