XAUUSD being led by XCUUSD by 13 days

There is no reason why an inverted Copper chart should look like the Gold chart, but leading by 13 days (April 21=now). But it does look like it. I have bought at market (1290) for 1335 with a tight 1280 stop. RR 4.5:1.

Very small size, as I have no other. evidence.