The dollar hit an 11 ½-year high against the euro and a seven-year high against the yen this week, and that's not good for stocks, says Russ Koesterich, chief global investment strategist for BlackRock.

"You've got the Dollar Index up about 23 percent from the summer lows, and people are realizing this is starting to bite into earnings" he tells CNBC.

A host of companies, ranging from IBM to Johnson & Johnson have reported a negative impact on their profits from the dollar's ascent.

A strong dollar curbs U.S. companies' exports by making them more expensive in foreign currency terms. And it lessens the value of their overseas earnings, which are worth less when converted into dollars.

Given the lofty levels of price-earnings ratios, stocks will have a tough time posting gains from here without earnings growth, Koesterich notes.

Koesterich thinks the dollar is due for a correction at some point this year, but that the bullish long-term trend remains in place.

"I think the dollar's going to continue to appreciate. It's going to be a two-way mark and we'll get a pullback some point this year because as we all know that this is an incredibly crowded trade," he explains.

"But the fundamentals are what they are, and the reality is the U.S. is going to outgrow Europe and Japan, the path of U.S. monetary policy is very different than the rest of the world and you've got a much lower current account deficit because of domestic oil production, all of which favor a stronger dollar over the next few years."

When it comes to stocks, John Hussman, Hussman Investment Trust's president, is a growling bear.

"We continue to observe one of the most overvalued, overbought, overbullish syndromes in the historical record, combined — and this feature is central — with deterioration in market internals suggestive of a shift toward risk-averse preferences among investors," he writes in his weekly market commentary.

"The resulting combination places current conditions among instances that we identify as a 'Who's Who of Awful times to Invest.' . . . We continue to view the stock market as vulnerable to significant downside risk both in the near-term and over the completion of the present market cycle."

Stocks have soared in the past six years, with the S&P 500 index tripling since 2009.

Related Stories:

• UBS' Hoefert: Don't Fear a Strong Dollar
• Brookings Senior Fellow Barry Bosworth: Strong Dollar Is Indeed the Biggest Threat to Our Economy