Sounds great for America, but it's a problem for stocks, and it's one of the reasons Goldman Sachs thinks the market will barely budge in 2016.

The strong dollar can pressure stocks in two ways: It makes American products more expensive overseas, so big U.S. multinationals have a tough time competing. And what international profit they do make is worth less when converted into dollars.

The dollar has been on a tear thanks to the relatively good U.S. economy and increasing signs the Federal Reserve will finally raise interest rates. The greenback is rapidly approaching parity with the euro. (One euro is currently worth $1.06.)

Goldman has advised clients to buy large U.S. companies that generate the vast majority of their sales at home.

"Divergent monetary policies (Fed tightening vs. ECB and BOJ easing) will strengthen the U.S. dollar and benefit some stocks and harm others," Goldman wrote in a recent report.

The "strong dollar regime" means stocks with high U.S. sales will outperform those with high international sales, the report said.