Trading the news: USD up, USD/JPY should go down

Beginner Questions
1

Trading with a Directional Bias | Trading the News | Learn Forex Trading

In this class it says that if the unemployment rate drops, USD will be weaker - which I can understand.

But then it says if USD weaken, you gotta short USD/JPY - which doesn’t make sense to me.

If USD becomes weak and that JPY doesn’t change, the pair USD/JPY should move UP, right? so you should LONG it and not SHORT it…

Can anybody help me understand?

2

For the scenario you painted, USD/JPY should move down instead of up.

You can plug in some simple figures to help you see the direction of movement:
Assume at the beginning that USD=10 and JPY=1, so USD/JPY=10
Assume USD weakened to 5 from its original value of 10, and JPY is unchanged, so USD/JPY now becomes 5
In effect, USD/JPY has gone down when USD went down and JPY remained unchanged.