Normal Market Size
Normal Market Size is of limited importance to private investors. Normal Market Size (NMS) is the SEAQ classification system that replaced the old alpha, beta, gamma system.
Normal Market Size is a value expressed as a number of shares used to calculate the minimum quote size for each security.
In plain english it's the amount of shares in a deal which the market can comfortably handle. This number will vary from company to company and depends upon the number of shares in issue and the likely demand.