NEW YORK (TheStreet) - Investors are indecisive on Wednesday, with the S&P 500 ETF (SPY) - Get Report moving higher by 0.5% before falling to a decline of 0.5% on the day. Currently, the ETF is flat in the session.  

China remains front and center, Pete Najarian, co-founder of optionmonster.com and trademonster.com, said on CNBC's "Fast Money Halftime" show. The country's recent PMI data was not strong, and it's clear it is slowing. 

Investors don't know how to value stocks right now, as the U.S. is doing fine, but the global economy is struggling, Najarian said. He also pointed out how poorly the Brazilian economy is doing. 

The Brazilian economy is contracting, while the Chinese economy is just slowing, added Jon Najarian, co-founder of optionmonster.com and trademonster.com. China matters because it's important to the Fed, which remains in the headlines following its no-hike rate decision last week, he said. 

Josh Brown, CEO and co-founder of Ritholtz Wealth Management, said there's been a psychological shift among investors. Instead of buying the dips, they are selling the rallies, he said, because they are no longer as bullish as they have been in the past. Utilities and consumer staples sectors are the best performing, which isn't a good sign for bulls, he said. 

It seems "fairly likely" that the S&P 500 will test 1,800, Brown added. 

While only about 2% of U.S. exports are to China, the country represents about 16% of the global economy, according to Jim Lebenthal, CFO and CIO of Lebenthal & Company. If China slows, so will other countries, which will ultimately hurt the U.S., he said, and that's why investors are concerned.

However, not all stocks have done poorly amid the turmoil. Nike (NKE) - Get Report , for one, is within a stone's throw of all-time highs. 

China is a part of Nike's growth strategy, but it's not where a majority of its revenues come from, Lebenthal said. He added that the Chinese consumer could see a slight slowdown, but it will only likely hold them back from buying cars and real estate, not Apple (AAPL) - Get Report iPhones and Nike gear. Pete Najarian agreed. 

H&R Block (HRB) - Get Report is also near all-time highs and is a stock Brown said he likes. The company had a terrible consumer banking business that tied up a lot of capital, he said. Management has since sold that unit and initiated a buyback, and business continues to look good, Brown said. 

Jon Najarian said not to forget about health care stocks like UnitedHealth Group (UNH) - Get Report and Tenet Healthcare (THC) - Get Report . The former is near all-time highs, while the latter has a lot of upside potential, he said. 

Biotech stocks have done poorly this week, with the iShares Biotech ETF (IBB) - Get Report falling 6%. However, the ETF is flat on the day. Pete Najarian said investors can own some of the bigger, low valuation stocks like Gilead Sciences (GILD) - Get Report and Celgene (CELG) - Get Report .

Shares of Volkswagen (VLKAY) are down more than 20% this week, but rebounded 8% on Wednesday on news that CEO Martin Winterkorn will resign following the company's admission to emissions cheating. 

Shares of General Motors (GM) - Get Report sold off over the past few days, too, but Lebenthal said that shouldn't be the case. GM has different engine-based vehicles than the ones in the Volkswagen scandal, and won't be hit by the same type of issues, he said. Consumers will still buy cars, and GM will be there to take in the sales. 

Brown added that the valuations for auto stocks continues to go lower, despite strong auto sales. This indicates investors expect the future auto sales to not be too bright, he said.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.