Chapter 04 · Section 4.1
Specialist
A specialist may act:
a) as a broker only;
b) as a market maker only;
c) as a broker or as a market maker, but not as both on the same day;
d) as both a broker and as a market maker.
Do not mix up the specialist (one specialist per option class) with the registered option trader (ROT, several per class). The two are responsible for keeping an orderly market in the Specialist System.