The NYMEX has futures and
options contracts for the oil and gas industry and for some
precious metals. NYMEX trades in two sessions, Regular
Trading
Hours (RTH) and and ACCESS (ACS) session.
The symbol template for futures is Smy where S
is the symbol, m is the month code for the trading session, and y
is the last digit of the year.
The symbol template for options on futures in the RTH
session is Smsss where S is the symbol, m is
the Call or Put month code, and sss is a threedigit strike
price. ACCESS option symbols temlate follows Smyssss
(note the year code and an additional digit for the strike price.)
Note: Options on futures require a "negative sign" or "dash" () before the symbol.
Strike Price: RTH = 3 digits / ACCESS = 4 digits


Regular Trading Hours (RTH) 
Any Instrument traded between 8:10 am and 3:30 pm 
ACCESS Hours (ACS) 
Any Instrument traded between 4:00 pm  8:00 am 