Dumbest Headline Ever
There are many things wrong with this headline. Firstly, Citigroup is not in the political forecasting business. Their number of 40% is low compared to Nate Silver's FiveThirtyEight site that currently has the chance of Trump winning at 47.5%. We know how Hillary does in televised debates (lost to Obama) when compared to Trump (trounced all opposition).
Their odds number is garbage.
Secondly, predicting an increase in volatility in anything before a presidential election is like predicting that the sun will rise tomorrow morning.