Just a year ago, if you mentioned "sovereign wealth funds," you probably would have gotten a blank stare. But, of course, this is now the hot thing in finance. More importantly, it looks like sovereign wealth funds are poised for strong long-term growth. In fact, Lehman Brothers (NYSE: LEH) recently set up a division to capitalize on the mega trend.

Sovereign wealth funds are found in many countries in Asia, Africa, Europe and the Middle East. It's the inevitable consequence of some major forces: strong economic growth in emerging economies, the fall in the US dollar and spikes in commodities prices, especially oil.

Global Insight, a research firm, estimates that sovereign wealth funds have grown an average of 24% per year for the past three years. They have about $3.5 trillion in assets, which is more than private equity and hedge funds combined.

No doubt, sovereign wealth funds have become a key element in global finance. For example, they contributed to about 28% of M&A deals (in January 2008) and about 10% of private equity transactions.

Global Insight forecasts that – by 2015 – sovereign wealth funds will exceed the value of the GDP of the US economy. And, I'm sure, the funds will also own a big chunk of it as well.

Tom Taulli is the author of various books, including The Complete M&A Handbook (www.mergerbook.com) and is also a principal in Averiware, which provides an ERP system to small and midsize businesses.