In the face of a global economic slowdown, Wall Street has been largely able to keep its footing because of the "bad news is good news" dynamic that's keeping the Federal Reserve on hold, market watchers said Wednesday.

"It's tough to find a growth rate in the economy that's going to be sustainable for the stock market," Jim Paulsen, chief investment strategist at Wells Capital Management, told CNBC. "But if it keeps up being weak, that's going to become an issue."