Copper's powerful rally may have a lot more juice in it.
Even though copper prices have soared nearly 30 percent this year, metals expert Michael Dudas doesn't see signs of cracks in the rally.
"I think the fundamentals on copper medium to longer term look very supportive," Vertical Research Partners' Dudas said Tuesday on CNBC's "Futures Now."
He urged investors in August to consider buying the precious metal. Since that Aug. 22 call, copper prices have gained more than 7 percent.
"The fundamental outlook for copper from a supply and demand basis looks positive," Dudas said Tuesday, as the metal traded around three-year highs.
He points to three bullish drivers: global demand growth exceeding expectations, some shortfalls due to labor unrest and mining declines.