A spotter lines up a truck before a container is loaded from a ship in the Seagirt Marine Terminal at the Port of Baltimore.

The U.S. economy grew in the third quarter at its fastest pace in two years, due largely to factors that are unlikely to last.

Gross domestic product increased at a 2.9 percent rate, above expectations and at the best rate since the 5 percent posted in the third quarter of 2014. The positive surprise comes as the Fed contemplates its second interest rate hike in more than 10 years, and Americans are set to elect a new president in less than two weeks.

However, a look under the hood shows that the U.S. is likely stuck in the same growth trap in which it has found itself since the Great Recession ended in mid-2009.

Many of the gains came due to a surge in soybean exports.



Soybeans? Yes, there has been a record bumper crop this year in the U.S., and strong demand from China helped fuel an export bonanza. However, that's not expected to last, and the U.S. also is likely to face competition in the market.

But there were other factors besides soybeans not to like in this report.