Stop and limit orders during weekend and holiday hours work different during times when some or all of the markets are closed. When trading is halted due to a holiday or weekend, it is important to note how stop and limit orders are treated.
If the currency cross opens at or beyond your stop or limit rate then your stop or limit will be filled at that opening market rate. This means that your stop orders may be filled at rates that are poorer than the order rates. Likewise, your limit orders may be filled at rates that are better than the order rates.
See the example below:
EUR/USD closes at 1.2400 on Friday.
GBP/USD closes at 1.7650 on Friday.
You have a Buy Stop on EUR/USD at 1.2425.
You have a Buy Limit on GBP/USD at 1.7625.
When the market opens on Sunday the following are the opening market rates.
Therefore, your EUR/USD Stop will be filled at 1.2440.
Also, your GBP/USD Limit will be filled at 1.7605.
You can see from the above example that leaving Buy Stop and Buy Limit orders over the weekend can cause unforeseen risks to forex traders.