Conventional wisdom holds that commodities and commodity stocks typically outperform the rest of the pack in the late stages of a bull market. But Margie Patel, managing director and senior portfolio manager at Wells Capital Management, thinks this time is different.

Why? By now, everyone is just beginning to realize new technologies for extracting oil and natural gas are going to stand the energy business on its head over the next decade. This has major implications for other related businesses, from corn to commodity chemicals.

But Patel also points out that the “big driver of demand” in recent years has been emerging markets, particularly China. These nations have built out their infrastructure, triggering an explosion in the demand for copper, coal, steel and cement.

Just take a look at all those empty cities in China today. “I think the heavy years of such expenditures are largely behind us, and further demand will be more muted, as the rate of infrastructure investment slows.” Over time, she believes, emerging market commodity demand will more loosely mirror modest growth for infrastructure demand in the developed world.

Fracturing has produced a gas glut in America to the point where some wells are being temporarily shut down. But eventually, new uses for gas, from trucking to rail transportation, could well materialize. This, in turn, could curtail demand for coal and diesel fuel, she notes.

Patel’s remarks just happen to occur at the same time as some big brokerages have downgraded such commodity-related stocks including Deere and Rio Tinto. And if the future for copper is so bright, why is leading producer Freeport McMoran spending a fortune to try to re-enter the oil business it exited years ago?

Agriculture remains a wild card. There is little question that the demand for food will surge in the next decade. But as Patel notes, agricultural yields have been raised by genetically modified seeds. So here again, technology is playing tricks with market dynamics.

Finally, when it comes to gold, Patel thinks it is hard to see prices advancing significantly from current levels unless there is explosive inflation. “If these views prove too negative about commodity supply/demand, as an investor, it can [still] be hard to profit from commodity price increases if they occur,” she says. “Consider how poorly over time that gold miners, and to a lesser extent coal and copper miners, have performed relative to the underlying prices of the commodities.”