NEW YORK (TheStreet) -- Despite the weaker U.S. dollar, lower stock prices and increase in the VIX volatility index, June has been a disappointing month for the precious metals. 

The metals appear to be pressured by deflation, with gold faring the best, down 1.5%, said Mike McGlone, research director for New York-based ETF Securities. Silver, although it has been trending down, has stabilized for the most part as currency volatility has increased. It remains the only precious metal up on the year, albeit "barely," McGlone said.

While the deflationary trend could be poised for a reversal, the overall trend is down, he said.

"Look at what the People's Bank of China just did, they just cut rates for the third time this year," McGlone said. "They're not doing that because they want to, they're doing it because they had to."

Prudent investors should focus on the deflationary trend being in place and not try to pick a bottom, McGlone said.

If deflation is in fact transitory, as the U.S. Federal Reserve has hinted, and goes away, it would be good news for gold, McGlone said.

While bond yields are one of the best forward-looking indicators of inflation, oil may provide a crucial clue, he said.