Market-on-Open Order
Definition
Market-on-open (MOO) is an order type used in stock markets to execute at the opening auction price. The equivalent in forex (which trades continuously without an opening auction) is a market order timed to a specific session open — typically London open at 08:00 GMT or NY open at 14:00 GMT. EAs often automate session-open entries with strict timing windows.
In-depth: Market-on-Open Order
Market-on-open (MOO) in stock-market context means an order that executes at the opening auction price — typically the official 'open' print used to start the day's regular trading. The forex market has no equivalent opening auction because trading is continuous 24/5; the closest analogue is timing market orders to specific session opens.
Forex session-open conventions: - London open: 08:00 GMT (07:00 BST during summer) - NY open: 14:00 GMT (13:00 BST during summer) - Tokyo open: 00:00 GMT (typically 23:00 GMT on Sunday for the new trading week's start) - Wellington open: 22:00 GMT (effectively the trading week's start)
EA implementations of session-open entries: 1. Time check: the EA checks current server time against the configured session open. The server-time vs UTC offset varies by broker — IC Markets uses GMT+2/+3 depending on DST; FXOpen uses GMT; OANDA uses ET. EA must account for these to time entries correctly. 2. Session window: typical implementations open positions in a brief window after session open (first 5-60 minutes). Configurable as `OpenSessionAfterMinutes` (when to start considering entries) and `OpenSessionUntilMinutes` (when to stop). 3. Range definition: many session-open strategies require a pre-defined range (e.g. Asian session high/low) that the EA tracks before placing the breakout order. Implementation requires storing the range during pre-session and using it for entry conditions at open.