This graph shows the yield on a 10-year British government bond - or gilt - over the last 48 hours. It contains the definitive answer to the question: how will the markets take the hung parliament.

Let me talk you through it. The graph shows gilt yields. Higher is bad - because it reflects the market's perception that lending to Alistair Darling is more risky.

On election day (left hand side) the gilt markets hover nervously. Then at 8am today they wake up worried: the graph starts higher and works its way up through several ticks. Then at 1043 Nick Clegg nominates the Tories as his first preference coalition partner. Immediately the risk indicators fall back.

But then they build again as Gordon Brown goes public with his determination to try and form a coalition.

Then at 1400 David Cameron makes his detailed pitch to try and get the Libdems on board. And the graph falls back.

The human story is, say my City sources, the City just did not see the strong Labour fightback in the urban areas. They thought a hung parliament would give the Conservatives a stronger moral claim on Downing Street than they actually emerged with. You could read this graph as the City liking the idea of a Libdem coalition. Or of the City worrying about the weak Libdem showing, because it allows the Libdems to be pulled into a Lib-Lab coalition that - they fear - might be tempted to soft-pedal on deficit reduction.

Tonight I'll be exploring this some-more on Newsnight at 2230GMT, together with emerging tipoffs of a major EU bailout plan aimed at stabilising the banking sector. But for now - that's the political day in a single graph.