PelatihA protected quote is a displayed best bid or offer that other trading venues may not trade through: an order executed elsewhere at a worse price must first take it, or be routed to it. In the United States it is the protected quotation of Rule 611 (One Quant Book 1, chapter 9); in the simulator and in firm_nbbo, a quote of at least one round lot.
Quantitative Finance · Glosarium