Directional movement is positive (plus) when the current high minus the prior high is greater than the prior low minus the current low, therefore, in my unprofessional opinion, the directional movement seems to be negative (-DM) because if you subtract the prior low from the current low it is greater than the current high minus the prior high, if I am reading it right. Pulling up a GDX chart, serms that is negative as well, I'll have to defer to you on the charts, I'm more of an Econ guy!
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