Led  - It would seem that the second part of the definition  you presented is somewhat out dated. Trading stocks today is now commoditized. You can make a trade for as little as a dollar, whether you are an individual or a company. National Bank for example does or did back office functions and trading functions for over 100 brokerages in Canada and TD does the same for another bunch of brokerages. That racking raking up commission stuff is a thing of the past with today's cost of trading and market surveillance techniques. Jitney trades could be happening with individuals or brokerages depending on the arrangements.

Someone is bound to ask where you can make a trade for a dollar, Interactive, at least in the USA.

tada