The long bull run for stock markets could be due a correction, according to one prominent emerging markets investor.

"There could be a substantial correction in the markets," Mark Mobius, founding partner at Mobius Capital Partners, told CNBC's Joumanna Bercetche Wednesday.

A 30 to 40 percent adjustment is "not unreasonable," he said, speaking on developed as well as emerging markets. "I'm not predicting that, I'm just saying we've got to be ready for that," he added. Mobius cited the long U.S. bull market, since 2009, as the reason for the correction.

"The catalyst I believe will come from continuing increases in interest rates. The (Federal Reserve) is definitely moving in that direction," he said. "When the Fed moves, everybody else has got to move in that direction."

Mobius also cited the potential impact of political changes on markets. "Any event could also be a trigger," he explained.

"But most importantly we've seen this long bull market that needs a correction," he said.

"Over the long term emerging markets will do very, very well," Mobius said, but he added that "the short-term corrections can be quite dramatic."