"UNG's management cannot predict what impact, if any, the resumption of creation activity will have on the price of the UNG units on NYSE Arca," warned the fund's managers in an SEC filing. "It is possible that the resumption of creation activity ... could reduce or remove any premium over NAV. Investors are cautioned that paying a premium over the NAV for UNG units can lead to additional losses for the investor in the event that the investor sells such units at a time when the premium is no longer present in the market price."

UNG shares shed roughly 2% Monday morning, extending a lengthy slide beneath resistance at its 50-day and 100-day moving averages. The security has given up about 65% of its value during the past 52 weeks, and it briefly dipped into single-digit territory earlier this month.

Meanwhile, option players appear to be betting that UNG's weak price action will persist during the near term. Within the first hour of trading, more than 15,100 contracts crossed the tape on the fund's October 15 call strike. Nearly 94% of this volume changed hands at the bid price, pointing to selling activity, and implied volatility is up 3.1% at last check. In other words, it looks as though traders are selling premium at this out-of-the-money strike, in hopes that UNG will continue to languish beneath $15 per share through October expiration.

Elizabeth Harrow is an analyst and financial writer in the research department at Schaeffer's Investment Research. She is featured in the video series Schaeffer's Daily Q&A on SchaeffersResearch.com.