Normal Market Size

Normal market size. Not a brag you want to put in your Tinder profile.

You run a restaurant. It's busy, but not overly stuffed. It's usually easy to get a table, no reservations needed. No trouble seating tables of two, three, four...even five or six. But then a party of 23 shows up. You have nowhere to put them. It's more than you can handle...more than the usual market asks out of you.

That situation basically defines the concept of normal market size. The term comes up in securities trading. It refers to the minimum number of securities (like stocks) that a market maker has to be willing to handle. Above that level, the market maker doesn't have to give a firm quote for bid and ask prices.

Like trying to seat a table of 23, those large orders (ones bigger than the NMS) are beyond what the market maker can be expected to handle.