Wall Street shares higher going into close
Yellen's testimony cheers markets
But US Inflation still a concern
Nvidia Corp among top risers, up over 4%
US shares are well ahead heading into the close.
The Dow Jones is 128 higher at 21,537, while the broader based S&P500 is 18.5 points higher at 2,443.
The tech heavy Nasdaq index is up over 70 at 6,263.
US crude is 0.78% higher, at $45.39 a barrel.
In London earlier, FTSE 100 closed 87 higher, at 7,416.
MID-SESSION
US stocks were trading higher at mid-session as Trump political rumblings continue and he heads to Paris for Bastille Day.
Federal Reserve chair Janet Yellen appears to have buoyed stock markets too with her dovish speech.
The Dow Jones is up 135 at 21,545, the S&P 500 is almost 19 higher at 2,444, while the tech heavy Nasdaq is 64 ahead, at 6,257.
US crude is also higher - up 1% to stand at $45.49 a share.
In stocks, NRG Energy Inc (NYSE:NRG) shares jumped 19.5% after the company reported the launch of its transformation plan.
Healthcare Services Group, Inc (NYSE: HCSG) added 11.2% as the group posted upbeat quarterly earnings.
On the downside, MSC Industrial Direct Co Inc (NYSE: MSM) shed 13.88% to US$74.96 as it reported an in-line profit for its third quarter, but issued weak earnings forecast for the current quarter.
1pm - London shares close higher
FTSE 100 finished the day strongly , up 87, or 1.19% as US shares also went north after Janet Yellen's speech before congress.
The UK blue-chip benchmark closed at 7,416 and registered the biggest single day gain since April as traders appeared to welcome the Fed chair's measured approach of how she sees the forthcoming months.
Interest rate rises will come but at a gradual pace, she suggested.
Oil was also surging ahead with a barrel of Brent crude- the UK benchmark -up 2.36% at the time of writing, to stand at US$48.10.
The biggest gainer on Footsie was Mediclinic International (LON: MDC), up 4.72% to 742.50p, while the top loser was legacy software specialist Micro Focus International, which shed 8.10% to 2,020p.
Its fall came after full-year results, though it was not the P&L (profit & loss account) that had traders nervous; it was the impending completion of its merger with the software arm of US information technology giant Hewlett Packard Enterprise.
US OPEN....
US shares bolted out of the box on Wednesday as markets appared to be calmed by Fed chair Janet Yellen's testimony before Congress.
She took a measured tone and suggested that interest rate rises will come but they will be gradual, not least due to the lack of action on the inflation front in the US, which does not seem to be rising despite a strengthening economy.
Yellen noted in the prepared speech that there had been an encouraging lift in household spending in recent months and manufacturers were being boosted from overseas spend.
The Dow Jones is up164 points at 21,573, while the S&P 500 added almost 18 at 2,443.
The tech heavy Nasdaq index gained over 53 points to stand at 6,246.
Fed Chair Yellen: Additional gradual hikes needed in next few years, inflation response to economy is key uncertainty, "the Federal Funds Ra
— Mason Pruner (@mpruner) 12 July 2017
In Toronto, the biggest exchange there, rose 138 points at 15,287.
The oil price was also forging ahead - up over 2.2% to $46.07 a barrel.
In companies, Fastenal Company (NASDAQ:FAST), the distribution major, added 2.11% as it stronger-than-expected results for its second quarter.
Quarterly earnings were $0.52 per share on revenue of $1.122bn against analysts' expectations of $0.50 per share on sales of $1.11bn.