Options begin trading as soon as an opening price for the underlying security may be determined. Options are opened for trading through a rotation that accepts orders and quotes for the series of calls that expire the soonest and have the lowest strike price. The rotation continues though all the near term series of call options and continues to the call options that expire further out. Once all of the calls are open, the rotation continues with the puts, starting with the puts with the highest strike price and the nearest expiration. The rotation in the puts continues through puts with lower strike prices and then to further out expirations.
Listed options also close on a rotation as soon as a closing price can be determined for the underlying security. A rotation can also be imposed during fast market conditions if the specialist or the order book official determines that the market is not operating in an orderly fashion. If a stock is halted, all option trading on that stock is also halted until the stock reopens.
Series 4 exam
Fast Markets And Trading Halts