I wonder if they won’t wish they’d stuck to their guns in a few months. If you look at a long-term chart of commodity prices, adjusted for inflation, you can see two things. The first is that they tend to move in long cycles — 20 years up and 20 down — and the second is that the up parts tend to coincide with periods of massive industrialisation.

There was a supercycle during the British industrial revolution, another during the industrialisation of the US and one during the great Japanese boom of the late 20th century.

We are due another: when commodity prices started to rise three years ago they had been in a nasty bear market for 20 years. But, more importantly, it is clear where the industrialisation to drive the new supercycle is coming from — China, India, various emerging Asian countries and, of course, Russia.

This adds up to the most extraordinary level of potential demand. Philip Richards at the RAB Special Situations fund (which has returned its investors’ money 20 times over since launch in 2003) pointed out to me that the commodities demand resulting from Japan’s industrialisation was driven by a population of about 150m people. This one, on the other hand, involves more like 3 billion.

His conclusion: “What’s happening now in the world is bigger than anything that has ever happened before on the demand side. It’s huge.”

There is constant concern among the commodity bears that faltering global growth will hit demand and hence prices, but it isn’t that simple.

Consider this: according to Richards, 26 Chinese cities are installing subway systems and the country as a whole is building 50,000 miles of three-lane highway, about the same as the entire American interstate network. The Chinese are planning to do this in five years, said Richards. The Americans took 40.

Then there are Chinese power grids. They are so over-stretched that power blackouts are a regular event all over the country. They all have to be upgraded. These are huge projects that will consume enormous amounts of copper and steel over the next decade, even if global GDP growth slows.

Then think about the energy needs of all these vast emerging economies. I’m in the process of reading a new book by a US investment analyst, Dan Denning, called The Bull Hunter. I’m not crazy about the title, but Denning does make some very interesting points.

Over the next 15 to 20 years the consensus forecast is that the world will be using about 125m barrels of oil a day. Right now we use a mere 85m and we’re already running near full capacity. That means that oil is going to be in short supply, but it also means alternative sources of energy — such as coal and uranium — are going to become more and more in demand. You wouldn’t have thought it, said Denning, but over the past four decades nuclear power has been the fastest-growing major source of energy in the world.

It is now used by 36 countries round the world, thanks to the fact that it is clean and cheap. The upshot? Denning agrees with Richards: the recent correction in commodity prices is merely a blip in what is really the start of a new supercycle. And blips, said Richards, are “symptomatic of the early stages of a bull market — confidence is always fragile at the beginning”.

Those who agree should take a look at RAB Special Situations. Investing directly isn’t for all of us (the minimum investment is £27,000) but RAB Capital has recently listed the RAB Special Situations Company on AIM, the idea being that all the money raised is invested in the fund. So, by buying the shares, you can now get exposure to it and the many coal, uranium and oil companies Richards holds.

Merryn Somerset Webb is a former stockbroker and now editor of Money Week. Her views are personal and investors should always seek professional advice.