Today, the US presidential race really gathers pace. Millions of Americans will cast their vote for Republican and Democrat candidates in the primary elections known as ‘Super Tuesday’. The results will give us a firmer idea of who the candidates will be in the November election.

While the US elections make for entertaining – and sometimes uncomfortable – watching, for investors, the outcome of the election itself and what it means for markets will be the focus.

Common perception suggests a Republican government and its pro-business polices should be positive for the US economy and ultimately stock prices.

However, research suggests a different story.

According to Fidelity International, which analysed the performance of the S&P 500, stock markets under Democrat presidents have on average outperformed those under Republican presidents, with average returns of 10% over a Democratic president’s term since 1928, against 1.8% for a Republican president.

It also shows that out of the 22 terms of office since 1928, four terms under a Republican president ended with negative returns in contrast to just one negative return under a Democratic present – Roosevelt’s second term in office.

Of course, past performance can’t be used as an indicator for future returns, but if these figures are anything to go by, investors will be hoping for a Hillary or Bernie win rather than a Trump triumph.