Strong Resistance

If you want to know how to draw strong supports and resistances as well as trend lines always use the monthly timeframe to have a clear picture of where the market is about to go. I was wondering why EURUSD drop this much, specially that the US Rate has not changed as well as EUR rate, But when I went to longer time frame I noticed that there is a strong down trend that been hit last week and price failed to reached it again that led the drop that we saw now in EURUSD