Global equity markets are tumbling to start 2016, prompting investors to seek out safe-haven assets, including gold. Although gold prices fell again last year, extending bullion's bear market to a third year, volatility to start 2016 has been a boon for gold and the related exchange traded funds. For example, the SPDR Gold Shares (NYSE: GLD), the world's largest gold ETF, is up 4.2 percent to start the year.

Gold's resurgence, albeit brief to this point, is proving to be a boon for miners stocks and ETFs such as the Market Vectors Gold Miners ETF (NYSE: GDX), the largest and most heavily traded gold miners ETF. Of course, leveraged bullish miners ETFs are benefiting in significant fashion as well.

Even with last Friday's loss of 7.3 percent, the Direxion Daily Gold Miners Bull 3X Shares (NYSE: NUGT) is still up more than 19 percent this month. NUGT's small-cap counterpart, the Direxion Daily Junior Gold Miners Index Bull 3X Shares (NYSE: JNUG), lost 8.3 percent last Friday, but is still up 15.3 percent this month. Those performances are enough to make NUGT and JNUG two of Direxion's best-performing leveraged bullish ETFs this month.

Despite those performances and the increased global market volatility that has increased gold's allure, traders are displaying little confidence that gold miners ETFs can extend their recent gains. To start this year, NUGT has lost nearly $20.3 million in assets while JNUG has seen $3.4 million in departures.

"Since gold is often viewed as a hedge against economic weakness, the strengthening U.S. economy has affected investment demand for gold, leading prices to fall. Goldminer stocks are an inherently leveraged play on gold prices. With expectations once again growing that the Fed will raise interest rates sooner rather than later, speculators are once again considering the leveraged trade on the miners," said Direxion in a recent research note.

Traders' doubts about the near-term outlook for JNUG and NUGT is further highlighted by recent volume statistics. For the five-day period ending January 7, NUGT's volume was nearly 14 percent below its trailing 20-day average while JNUG so a modest volume decline over that period, according to Direxion data.

Though past performances are not guarantees of future returns, a theme that has been prominent with leveraged gold miners ETFs is worth remembering. Traders have previously eschewed the leveraged gold miners ETFs that are going up in favor of the leveraged gold miners funds that are struggling. So perhaps that trend could replay itself, leading to more near-term gains for JNUG and NUGT.