LONDON — When Britain voted in 2016 to leave the European Union, its currency plummeted on world markets, reflecting agitation over the economic and financial disruption that seemed to lie ahead.

Three years later, with Brexit still not achieved, trading in the pound has been telling a different story.

After weeks of steady gains ahead of Thursday’s general election, the pound jumped as exit polls suggested a victory of the Conservatives and Prime Minister Boris Johnson, who campaigned on completing the rupture with Europe. The pound held on to most of its gains on Friday, after official results confirmed that the Conservatives had indeed won a majority.

In currencies, as in other markets, traders like certainty.

“The market sees a Tory majority as the best outcome in the short term,” said Lee Hardman, a currency economist at MUFG, a Japanese bank. “It gives you more clarity over the direction of Brexit.”