No one can predict the Forex market, but we do have plenty of evidence from the past of how the markets react in certain situations. What has happened before may not be repeated, but it does show what is possible. Therefore, it is important to look at the history of the currency pair you are trading. Think about what action you would need to take to protect yourself if a bad scenario were to happen again.
Do not underestimate the chances of unexpected price movements occurring. You should have a plan for such a scenario, because they do happen.