Shares in Standard Chartered surged after analysts at Barclays and Bernstein raised their ratings, highlighting the recent appointment of a former JPMorgan banker as its new boss. Barclays lifted their stance from 'equal weight' to 'overweight', while Bernstein upgraded by two notches from 'underperform' to 'outperform'.After a slow start, energy stocks such as BG Group pushed into positive territory, extending strong gains made on Tuesday on speculation about tax breaks in the North Sea. BG Group also announced first oil from its part-owned Knarr field in the North Sea offshore Norway.Housebuilders such as Taylor Wimpey were making decent gains. "Housebuilding shares could also get a boost if we get investment initiatives to build more properties, given the pressure on housing," said analyst Michael Hewson from CMC Markets.Smiths Group fell after first-half underlying profits at the engineering company stumbled 3% on the hurdles of foreign currency and the lower oil price.Mining stocks were also retreating after solid gains on Tuesday, with Fresnillo, Antofagasta and Rio Tinto in the red. Antofagasta in particular was feeling the effects of a downgrade by Beaufort Securities to 'hold'. RisersStandard Chartered (STAN) 1,035.50p +7.31%CRH (CRH) 1,772.00p +5.04%Hargreaves Lansdown (HL.) 1,227.00p +4.51%Royal Mail (RMG) 449.70p +4.17%St James's Place (STJ) 963.50p +3.60%Ashtead Group (AHT) 1,128.00p +2.83%easyJet (EZJ) 1,835.00p +2.40%Taylor Wimpey (TW.) 152.80p +2.34%United Utilities Group (UU.) 931.00p +2.14%Land Securities Group (LAND) 1,259.00p +2.11%FallersFresnillo (FRES) 648.00p -1.67%Weir Group (WEIR) 1,755.00p -1.40%Rio Tinto (RIO) 2,838.00p -1.24%Antofagasta (ANTO) 680.00p -1.02%Burberry Group (BRBY) 1,855.00p -0.80%Randgold Resources Ltd. (RRS) 4,646.00p -0.56%Glencore (GLEN) 281.00p -0.48%SABMiller (SAB) 3,680.50p -0.42%Royal Bank of Scotland Group (RBS) 349.30p -0.40%Lloyds Banking Group (LLOY) 79.24p -0.28%