you should see a lawyer.

but the black letter law as of when i was a lawyer (2010) is that you can trade on an overheard conversation (see the switzer case involving the famed oklahoma football coach).

you don't have a fiduciary duty to the company and you don't inherit the duty from the tipper because the tipper tipped without personal benefit.

edit a reliable reference (contra some of the other sources cited in this thread): http://www.concurringopinions.com/archives/2009/08/insider-t...