Legendary investors are made by their ability to anticipate the trends that will shape markets well before those trends are widely seen or priced into the market. Super-investor Warren Buffett closed out much of his derivatives exposure from subsidiary General Re by 2005, well before derivatives hit the wall from 2007 to 2009, which helped him avoid the meltdown.

Now a growing chorus, including the voices of the Obama administration and prominent economists such as Fed Chairman Ben Bernanke, is calling for a change that will cause a massive shift in international trade. This means agile investors have an opportunity to play this change before it's fully reflected in share prices.

Excellent exchange
This massive shift concerns China's exchange rate, which many analysts view as simply too low and as destabilizing for global trade. Since 1995, China has kept its rate effectively pegged to the dollar, at a low level that makes its exports ultracompetitive in world markets.

Now experts such as Nobel laureate Paul Krugman still see the renminbi as underpriced. Goldman Sachs is predicting a rise, and Wells Fargo expects that the renminbi could gain as much as 15% by the end of next year. Those would be massive tailwinds to well-positioned Chinese stocks.

Here's why the renminbi is likely to rise soon.

To maintain a fixed exchange rate, China has had to buys tens of billions of dollars every month in order to resist the pressure toward currency appreciation caused by the inundation of foreign capital into its too-cheap markets.

As if that weren't enough, China's exchange rate policy is throwing a spanner into the work of policymakers to get developed economies humming along again. As the Federal Reserve reduced interest rates to jump-start America, the dollar depreciated relative to other currencies. Since the renminbi was tied to the dollar, U.S. exports gained little to no advantage against China, while Europe suffered further. China effectively "piggybacked" American efforts.

As Krugman explains, "In the current environment, with high unemployment around the world and policy interest rates as low as they can go, this is a predatory, beggar-thy-neighbor policy."

Throughout this saga, China complains bitterly about high inflation, and laments its extensive holdings in dollars. As both Bernanke and a group of Citigroup analysts noted, currency appreciation would help tame China's inflation, helping it buy the natural resources it so desperately needs.

How now, Mao?
As I hinted above, one solution to this situation is for China to allow the renminbi to appreciate relative to the dollar. That's the line taken by the Obama administration, which recently informed China that currency policy will occupy a prominent place in their economic talks.

If China were to allow its currency to appreciate, the immediate effect would be to hurt its export-reliant industries such as manufacturing. That increase in costs would slap major importers from China such as Wal-Mart (NYSE: WMT) and Ford (NYSE: F), which source billions in products from there.

However, the currency move would help American companies that are quickly expanding Chinese operations. Starbucks (Nasdaq: SBUX) and Yum! Brands (NYSE: YUM), with its massively popular KFC franchises in China, are looking to grow thousands of operations. But obviously, they're not pure plays on China and won't experience the full burst of the renminbi's appreciation. To find such an opportunity, it's a good idea to look at Chinese companies.

But rather than haphazardly buying Chinese stocks and hoping that American and Chinese politicians can come to an agreement, a better strategy is to find absolutely solid Chinese companies that are thriving now and will continue to thrive if and when the renminbi appreciates. Then currency gains can become the tailwind to a great investment.

Stocks such as these would be likely winners from currency appreciation:

Company

Industry

Trailing Return on Equity

Trailing P/E

China Mobile (NYSE: CHL)

Telecom

24.3%

15.1

China Green Agriculture (NYSE: CGA)

Agriculture

26.5%

15.1

RINO International (Nasdaq: RINO)

Environmental Services

41.6%

9.1

Source: Capital IQ, a division of Standard & Poor's.

By buying an efficient and reasonably priced company such as China Mobile, you have the opportunity to profit from an undervalued company as well as the appreciation of the renminbi. Better still, your investment gains in dollar terms even if the stock's relative valuation remains the same. That is, because currency appreciation is driving the stock up and not investors willing to pay a higher P/E, a cheap company is still cheap and you've captured a currency gain for free. Tack on the power of multiple expansion, and you can quickly see blockbuster returns.

An interesting proposition
There is plenty of noise in policy circles about China's cheap currency, but of course China is not the only place where you can use exchange rates to juice your returns. At Motley Fool Global Gains, advisors Tim Hanson and Nathan Parmelee have recommended rock-solid companies across the globe whose stocks are poised to gain from excellent fundamentals and a falling dollar. You can read all about them by clicking here to join Global Gains free for 30 days.

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Fool contributor Jim Royal, Ph.D. doesn't own shares of any company mentioned. China Green Agriculture is a Global Gains recommendation. Ford and Starbucks are Stock Advisor selections. Wal-Mart is an Inside Value pick. Motley Fool Options recommended a bull call spread on Yum! Brands. The Fool owns shares of China Green Agriculture and China Mobile. The Fool has a disclosure policy.