For the last several years, a growing chorus of global growth believers has espoused the benefits of investing overseas. But if you look at some exchange traded funds (ETFs) over the last month, a different picture is taking shape.

Several asset classes have gone flat in the last month and simply aren’t doing much of anything. Take, for example, iShares MSCI Emerging Markets (NYSEArca: EEM), which is down 0.7% in the last month. Or Global X China Materials (NYSEArca: CHIM), down 0.8%; or the SPDR S&P World ex-US (NYSEArca: GWL), which is down 0.5%.

Now look at what’s on top for the last month. There’s one clear standout: U.S. small caps.

Rydex S&P SmallCap 600 Pure Value (NYSEArca: RZV) is up 11.2%; PowerShares S&P SmallCap Industrials (NYSEArca: XLIS) is up 10.7%; Schwab U.S. Small-Cap (NYSEArca: SCHA) is up 7.5%.

For years, our mindset has been that returns can’t be found here like they can elsewhere. But if you look at what small caps have been doing, you’ll find that that clearly isn’t true right now. If this continues, 2011 could easily become the year of the good old U S of A.

But that doesn’t mean emerging markets and agriculture are done. Developing economies should continue to grow, while their middle classes demand more food and materials for building up their economies.

The real lesson here is to look around – sometimes new opportunities present themselves and we’ll miss them if we’re not paying attention. Have a simple strategy to find your spots; we use trend following, which you can learn all about here. If you’re a premium member, sign up for alerts so you never again miss a trading opportunity.

Read the disclaimer; Tom Lydon is a board member of Rydex|SGI. For full disclosure, Tom Lydon’s clients own shares of SCHA.