Yesterday, gold broke out, pushing GDX together with it.
I found interesting that buying was very strong even after the gap-up.
We can see below that volume was higher than usual, which confirms the Breakout.
The Breakout Calculator shows that on the base of the data of two days ago (the close of the day before the breakout,) if we use the close of yesterday ($20.78) as a breakout price, we can see that the statistics for the past 500 days are excellent.
This means that you can enter today at yesterday's close and expect to make good money.
You can see below that you could still enter between $20.30 and $21.34 and still make money.