Greg is engaged in "insider trading".
Insider trading is the purchasing or offering of a security by somebody who approaches material nonpublic data about the security. Insider trading can be unlawful or legitimate contingent upon when the insider makes the exchange. It is illicit when the material data is as yet nonpublic.
Illegal insider trading incorporates tipping others when you have any kind of nonpublic data. Lawful insider trading happens when chiefs of the organization buy or offer offers, yet they reveal their exchanges legitimately.