The pound was yo-yoing against the dollar and the euro on Thursday, fluctuating in the light of negotiations between London and Brussels over their Brexit trade relations before finally registering lower against the currency European.

Reversing the trend of the day before, the euro, for its part, rose slightly against the greenback as caution replaced optimism on the possibility of an agreement in Washington for a new economic aid package before the 'presidential election.

Around 7:00 p.m. GMT (9:00 p.m. in Paris), the pound lost 0.21% against the greenback at 1.2893 dollars and 0.43% against the euro at 91.10 pence for one euro.

“The pound has been in a wild see-saw after a series of Brexit news,” summarized Neil Wilson of Markets.com.

It first "slipped in the morning as the EU lodged a complaint about the internal market bill", with European Commission President Ursula von der Leyen announcing the launch of legal proceedings against the British bill relating to Ireland.

Those losses were then "completely reversed" after the Financial Times reported that "the EU and UK had found a landing zone on state aid, potentially clearing the way for a trade deal", explained Eric Nelson of Wells Fargo Securities.

It thus rebounded "aggressively" up to $1.2951, briefly reaching a two-week high but without testing the ceiling of $1.30.

But in session in New York, the British currency then largely lost the ground gained, against the dollar as the euro.

"We remain of the view that a Brexit trade deal is likely, which should provide near-term support for the pound," said Eric Nelson, but said investors "should temper their support for the pound. following a trade agreement, in particular against the euro".

"The positioning of the pound is already a bit long and the UK is still in the grip of the deepest recession of any G10 economy, as well as a rapidly accelerating second wave of Covid," a- he said in a warning to those betting on a rise in the British currency.

In addition, the euro continued to progress, but more modestly than in the morning against the greenback, taking 0.22% against the dollar, at 1.1747 dollar.

The day before, "the depreciation of the dollar was reinforced by optimism that a new package of budgetary measures could be accepted soon", explained Derek Halpenny, analyst for MUFG.

But Wednesday's enthusiasm had given way to more caution on the outcome of negotiations between Republicans and Democrats for a massive recovery of the American economy. “In my opinion, Republicans in the Senate are unlikely to support another $1.5 trillion aid package,” warned the chief analyst at Wells Fargo Securities.