British bookmakers William Hill were first out of the gate, offering 10/11 odds that it is a boy, and 10/11 odds it will be a girl. Odds of 20/1 are also being offered for the birth of twins, a drop from earlier in the day when odds of 32/1 were being offered (as the FT's Hannah Kuchler points out, severe morning sickness, as reportedly experienced by Kate, is more common amongst mothers carrying multiple babies).
As has become their trademark style, Paddy Power has followed up with some more exciting ways to part with your money. Currently the Irish bookmaker is offering bets on "Next Monarch", "Godparents", "Multiple birth?", "Sex of first child", "Name of first child", "Hair colour of first child", "Weight of first child", and "Time of birth of first child".
Amongst those you'll find some interesting outside bets — 6/1 odds for a ginger baby, for example, 250/1 odds for the female child being called "Fergie", or Victoria Beckham at 100/1 for being named the godmother.
According to one odds checking website, the early favorites for the name are John and Robert if a boy or Anne and Francis if a girl.
Of course, there is always the danger of inside information with something like this. Trevor Kavanagh, formerly politics editor of the Sun, says that his paper was able to get a scoop in 1988 after a large number of bets on the name "Beatrice" at a betting shop suspiciously close to Balmoral Castle.
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