It took several sessions to definitively mark the channel barrier.
However, with today's action we can see that the channel is now well defined and GDX is accelerating lower.
The corresponding Direxion Daily Gold Miner Bear 3X ETF (NYSEARCA:DUST) is having an excellent day at a gain of 11.43% as of this post.
Chart by TeleChart
It so happened that the right channel line was also correlated with a Fibonacci time-frame of 34-trading sessions (from contact with the left channel line).
This gives us a clue that future pivot points in this market may correspond with other Fibonacci time-relationships.
Disclosure: I am long DUST.