Strong US Dollar a Headwind for Stocks?

Fundamentals are strong and the U.S. dollar has helped the Dow Jones Industrial Average and the S&P 500 hit new highs Friday, the CNBC "Fast Money" pros said, but can the stock rally last?

"It's astounding. It just continues to go higher," Brian Kelly of Shelter Harbor Capital said. "I do think what the story of today is the U.S. dollar."

Kelly noted that the dollar was seeing levels not seen since 2008, which is helping the U.S. stock market.

"Eventually, you have to start asking questions about what that's going to do to multinationals," he added.

(Read More: Stocks Rally for 4th-Straight Week; Dow, S&P 500 Jump to New Highs)

Tim Seymour of pointed to growth in gross domestic product in emerging economies:

Russia posted a 1.6 percent increase, Brazil and South Korea at a 1½ percent increase and Mexico with 1.2 percent GDP growth.

"The U.S. is a 2½ percent," Seymour said. "The U.S. is actually growing a lot faster, a lot higher than a lot of these growth economies, so it's a case where I think that the fundamentals are better right now."

Seymour added that it wasn't time to get worried about the U.S. dollar just yet.

"Let's wait for the time where we get worried about the multinationals around earnings time when the dollar is a headwind," he said.

The next concern for the market will likely be about valuation, Seymour added.

"I don't think we're terribly cheap here," he said.

Trader disclosure: On May 17, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Brian Kelly is long TLT; Brian Kelly is long TREASURIES; Brian Kelly is long COPPER; Brian Kelly is long DOLLAR; Brian Kelly is short GOLD; Brian Kelly is short SILVER; Tim Seymour is long AAPL; Tim Seymour is long BAC; Tim Seymour is long WMT; Tim Seymour is long SBUX; Tim Seymour is long WLT; Tim Seymour is long TSL; Guy Adami is long C; Guy Adami is long GS; Guy Adami is long INTC; Guy Adami is long AGU; Guy Adami is long MSFT; Guy Adami is long NUE; Guy Adami is long BTU; Josh Brown is long AAPL; Josh Brown is long XLU.