If you own shares of any miner of copper, lead, tin, nickel, zinc, or aluminum, think about sending a thank you note to investment companies such as ETF Securities, Goldman Sachs, JPMorgan Chase, Deutsche Bank, Citigroup, and Credit Suisse. They’re about to make you money.

These companies have noticed the big appetite for ETFs (exchange traded funds) that actually buy and hold gold. That gives investors an easy way to hold the actual metal without having to worry about how to take delivery and where to put a few hundred pounds of the yellow shiny stuff.

For example, SPDR Gold Shares (GLD), the largest gold ETF, holds $55 billion of the metal. That’s 41.8 million ounces or 1302 tons of gold. The ETF, which dates back to November 2004, is the second largest ETF of any kind.

Nobody ever accused Wall Street (or its international counterparts) of ignoring a good thing. If an ETF that holds gold can gather billions in assets from investors who want to own the real thing rather than shares in gold mining companies, why not ETFs in copper, nickel, tin, aluminum, or any of the base industrial metals racking up new highs on the London Metals Exchange every day. On Monday October 11, ETF Securities announced that it will launch ETF funds that will hold physical copper, aluminum, lead, tin, zinc, and nickel. The other investment companies I listed up top either have products in front of regulators or are thinking of launching an ETF base metals product.

Now I don’t know if a copper or nickel ETF is a good investment—I’ve got my doubts (see below)—but I do know this would be great news for investors that hold shares in any base-metal mining company.

That’s because any metal that sits in a vault somewhere isn’t available to make copper wires, or aluminum cans, or lead batteries, or nickel alloys such as stainless steel, or tin solder, or zinc die castings for cars. That’s not a huge issue for gold, which has relatively few industrial uses. But now we’re talking about taking tons of industrial metals, removing them from industrial markets, and storing them as investment products. That’s a  very different story.

At a time when demand for these industrial metals is strengthening and when supply isn’t keeping up with demand because of aging mines and investment in new mines during the global financial crisis, I say bring ‘em on. Goldman Sachs is already predicting that copper prices will hit $11,000 in just 12 months—that’s a 35% jump from today’s price of $8,345 a metric ton (which is in turn just $600 a ton below the all time high set in July 2008).

Demand from base metals for ETFs is just what investors in the shares of metal miners need to feel that that predictionis conservative.

Of course the base metal ETFs may not take off. I don’t think they’re especially great investment products. An ETF that holds physical gold works because gold is physically dense for its price. You only need to transport and store an ounce to have $1300. Copper sells for $8,345 a ton so you need to transport and store 342 pounds to get that $1300. Zinc sells for $2,380 and aluminum for $2430 a metric ton. You’re talking about storing half a ton or so instead of an ounce to represent $1300.

That means base metal ETFs are looking at radically higher transportation and storage costs than gold ETFs. That’s not going to help the returns on these investment vehicles.

But, hey, I hope they work. I hope they take lots of tons of base metals off the market. That would certainly help investors who own shares in the companies that dig this stuff out of the ground.