LONDON, Sept 18 (Reuters) - Financial market bets on the swing likely over the next 24 hours in the value of Britain's pound doubled on Thursday as Scots began to vote in a referendum on independence that polls suggest is too close to call.
The overnight sterling/dollar implied volatility rose to a high of 34.75 percent, almost ten times levels seen a month ago, having closed on Wednesday at around 12.75 percent. The overnight options will expire on Friday, when results for the Scotland vote will be announced.
The pound itself traded slightly higher at $1.6305, staying well above a 10-month low of $1.6051 struck last week. It has bounced from those lows after most polls showed those intending to vote to stay in the union were slightly ahead.
Euro/sterling overnight implied volatility also shot up to trade over 33 percent, from around 9 percent on Wednesday.
Sterling also gained 0.1 percent to 78.98 pence per euro (Reporting by Anirban Nag; editing by Patrick Graham)