Can you dig it?
This year's best-performing exchange-traded funds are all gold plays. Among ETFs with more than $500 million in market value, the top dog is triple-leveraged gold miners product (NUGT), with an insane 315 percent rally. But nipping at its heels is unleveraged gold mining pick (GDXJ), which tracks smaller, or "junior" gold miners, which tend to be more volatile. That ETF is up 98 percent this year, outperforming its bigger brother (GDX), which is also a VanEck Vectors product.
What's incredible is that even after nearly doubling this year, the GDXJ is still down 73 percent over the past five.
The junior gold miners tend to be heavily levered to the price of gold; over the past five years, the GDXJ has a beta of 1.7 to the metal, which means that it tends to trade in the same direction as gold but with almost twice as much volatility. That compares to the 1.4 beta that the GDX has to gold.
Read MoreGold gains ground as dollar retreats
Also helping, according to Erin Gibbs of S&P Investment Advisory, is the Canadian dollar's rise against the U.S. dollar. The Canadian dollar's moves are significant, given that many of the companies in the ETF are Canadian, and a rising Canadian dollar helps their values rise in terms of greenbacks.
However, Gibbs warns that from a valuation perspective, the stocks have become "incredibly overvalued."
On the other hand, if gold stays on the incline, the miners should continue to perform well, and the junior miners should perform even better.
If gold "can bust through the $1,300 level, I think gold really goes to $1,350," Boris Schlossberg of BK Asset Management predicted Friday on CNBC's "Power Lunch." "That big move could really have a push on miners because they'll respond to a very positive move in gold."