The pound climbed to its strongest level since December amid speculation that U.K. voters opted to remain in the European Union.

Sterling jumped Thursday as opinion polls conducted before voting started showed a lead for the ''Remain'' camp, adding to speculation the U.K. would stay a part of the 28-member organization. Voting closed at 10 p.m. London time and the first official results are expected as soon as midnight. A YouGov Plc survey conducted on the day of the vote showed a 52 percent share for the status quo.

The pound has swung vigorously since the start of the campaign in February, acting as a barometer for sentiment and reflecting the side of the debate in the lead. It dropped to a seven-year low that month when former London mayor Boris Johnson announced his support for Brexit. Just last week it was as low as $1.4013 when the ''Leave'' camp appeared to be ahead.