GBP/USD is trying to hold onto 1.37, trading near the March lows. The US dollar is rebounding the from dovish Fed-induced blow. Concerns about Britain's vaccine supplies and Brexit-related issues are weighing on sentiment.

Pound/dollar has been extending its falls after breaking below the uptrend support line, as the four-hour chart is showing. Momentum remains to the downside and the Relative Strength Index is above the 30 level, outside oversold territory.

Overall, bears are in control. Critical support awaits at 1.3670, which was March's low point. It is followed by 1.3610, a cushion from January, and then by the February trough of 1.3565. Some resistance is at 1.3705, a low point in late March, followed by 1.3780, the weekly high, and then by 1.3920, which worked as support last week.