Following success in the Nevada state primaries, Republican presidential candidate Donald Trump looks set to extend his lead in the race for the Republican party nomination.

According to NBC polls, Trump leads in four of six states going into Super Tuesday next week.

Mike Thompson, Managing Director and Chairman at Standard & Poor's Investment Advisory Services, said he didn't think investors knew how to respond to Trump's run.

"I think markets are in a kind of a state of disbelief. I don't think they've ever seen anything like this.

"The extreme between the two parties is really striking," he told CNBC Wednesday.

Thompson said the election process itself was like something that nobody has ever dealt with.

"It's like somebody broke all the rules.

"Its unfamiliar territory and it's hard to take a historical precedent and apply it in this situation," he said.