J.P. Morgan says there's still room for a global run-up in equities, but "the most important thing" is whether the world economy responds to efforts to spur its growth.

Accommodative policies by the Fed and the ECB, as well as increasing efforts by Chinese authorities to boost the world's second-largest economy, have helped fuel stocks' rally this year, said Tai Hui, J.P. Morgan Asset Management's chief market strategist for Asia.

"But for the rally to really continue, I think the most important thing we're watching out for is whether the global economy starts responding to a more dovish Fed, a more dovish ECB, to more stimulus from China," Hui told.