It is unlawful for an issuer or any person who is an officer, director or controlling person of an issuer or any other person whose relationship to the issuer gives him access, directly or indirectly, to material information about the issuer not generally available to the public, to purchase or sell any security of the issuer in this state at a time when he knows material information about the issuer gained from such relationship which would significantly affect the market price of that security and which is not generally available to the public, and which he knows is not intended to be so available, unless he has reason to believe that the person selling to or buying from him is also in possession of the information.