The central bank boss trod a fine line between cautiousness and optimism, and investors saw this as a sign to take on some risks.
They piled into miners and oil firms, which make up the bulk of the FTSE 100, sending the UK’s leading index of companies up 23.03 points, or 0.32%, to 7148.01.
Michael Hewson, chief markets analyst at CMC Markets UK, pointed out that the key issue helping traders were Mr Powell’s comments that the end of US Fed support – tapering – is still some way off.
He said: “The reinforcement of the message that tapering is not tightening, and merely a reflection of the improvement in the economy, has helped reassure markets that the central bank is not going to be hasty in removing accommodation.”
In London, the news sent shares in Anglo American, Antofagasta, Glencore BHP, BP and Rio Tinto into the top ten biggest risers.
Germany and France enjoyed similar boosts, with the Dax up 0.37% and Cac up 0.24%.
The dollar suffered a fall, with traders pulling money out of safe havens, into shares instead, pushing the pound up 0.18% against the dollar to 1.377. The pound was also up against the euro by 0.13% at 1.168.
In company news, it was a quiet one as boardrooms look to ease themselves into the long weekend.
Just Eat Takeaway shareholders took a shock, with shares closing down 7.5%, a fall of 519p to 6,407p.
The fall followed a decision by officials in New York that food delivery platforms, where Just Eat has a significant stake, can only charge a maximum of 15% commission for every food order.
The group behind the Daily Mail was a step closer to being taken private by its largest shareholder, Lord Rothermere, following the successful flotation of used-car business Cazoo in the US.
It was one of the conditions of a possible bid for the group by the business tycoon and focus now goes onto negotiations with pension trustees. Shares closed up 20p at 1,114p.
UK-listed Air Partner revealed the ultra-rich in the US have been hiring private jets to go away on their holidays at a rate high enough to offset the firm’s drop in business travellers. Shares soared 7.8% in early trading but ended the day up just 2.1% by close, up 1.8p at 86.4p.
Lender Amigo admitted the future remains uncertain despite managing to increase profit tenfold.
The business is facing a long list of complaints but the charges were in last year’s accounts, meaning this year’s showed a £15 million pre-tax profit in the first quarter of this year. But it booked a £284 million loss last year. Shares closed up 0.335p at 8.235p.
Go-Ahead group revealed its annual results would be delayed by three weeks to give auditors more time to go through the numbers. The Govia Thameslink and Southeastern railway owner saw shares stay flat at 977p
The biggest risers on the FTSE 100 were Anglo American up 90p at 3,084p; Antofagasta up 34.5p at 1,462p; Pershing Square up 60p at 2,590p; Glencore up 7.45p at 332.55p and BHP up 48p at 2,280p.
The biggest fallers were Just Eat Takeaway down 519p at 6,407p; Sainsbury’s down 9.4p at 310.4p; Ocado down 29p at 310.4p; CRH down 34p at 3,887p and Royal Mail down 4.1p at 490p.