Above all, markets crave certainty. Political instability inhibits investment and reduces the appetite for risk. Many business leaders would have viewed the general election result as a significant blow to those wanting the UK to withdraw from the EU single market and customs union. It also still leaves us with the very real prospect of an incoming Labour government - if another election is called in the not-too-distant future - committed to a seven percentage point increase in corporation tax and the re-nationalisation of the UK's energy companies and rail industry.
Whatever your views on the desirability of these proposals, it's difficult to imagine that the mere prospect of such radical measures won't stall near-term corporate decision-making. This corporate inertia could well be matched by legislative paralysis in Westminster, so it's conceivable that by the end of the year UK voters may be asked to return to polling booths to try to clear the way for a majority in the lower house.
Beyond making the actual business of governance somewhat problematic, it's difficult to predict how the formation of a minority government might play with the UK equity market. It's fair to say that traders have been more circumspect since overselling the market in the immediate aftermath of the EU referendum, but even if Theresa May does manage to cobble together a working arrangement with the Democratic Unionist Party, history suggests that it will be a shortlived affair.