When do you start to call yourself a professional? When do you stop to call yourself a professional?
Strictly speaking (from IB's website), a professional is:
(a) registered or qualified with: the Securities and Exchange Commission, the Commodities Futures Trading Commission, any state securities agency, any securities exchange or association, or any commodities or futures contract market or association, or
(b) engaged as an "investment advisor" as that term is defined in Section 201(11) of the Investment Advisor's Act of 1940 (whether or not registered or qualified under that Act), or
(c) employed by a bank or another organization that is exempt from registration under Federal and/or state securities laws to perform functions that would require him or her to be so registered or qualified if he or she were to perform such functions for an organization not so exempt.
Any person who does meet the above criteria (a,b,c) is considered a Professional Subscriber.