What is the difference between a regular opening and an auxiliary opening at the Amex?
A regular opening at the Amex occurs daily, except for expiration days when an auxiliary opening is conducted. Auxiliary openings are conducted once a month on expiration Fridays for stock orders relating to opening price settling index options, index futures, and options on index futures. During an auxiliary opening: (a) there is a 9 a.m. cut-off time for entry of on-open orders that must be tied to index expiration and marked OPG;* (b) opening order imbalances are published at 9 a.m.; (c) OPG orders may be canceled or reduced in size, but firms have to maintain a written record describing the rationale for these changes. Apart from the procedures highlighted above, other procedures during regular openings and the auxiliary opening are the same. *Note: Stock orders relating to opening-price settling contracts must be identified “OPG.” Firms entering these orders through AOF that are unable to identify orders as “OPG” may use a unique branch code or firm identifier (mnemonic) to identi
