Those "plenty of traders" were in the small minority. If they were in the majority, then the markets wouldn't have moved so much following the outcome! So yes

Those "plenty of traders" were in the small minority. If they were in the majority, then the markets wouldn't have moved so much following the outcome! So yes, before a messay probabilistic evet, there was a minority of experts who thought it would go one way...but a majority who thought it would go the other. Hardly obvious that Leave would win!