The FTSE 100 broke through and stayed above the 5,500 barrier today, closing up 0.81 per cent.
The index closed up 44.20 points to 5,533.40 despite falls from energy and commodity stocks.
Builders merchant Wolseley was up 13.78 per cent today, heralding rises for builders outside the FTSE 100, while ITV rose 6.70 per cent after group chief executive of RSA Insurance Group Andy Haste was named as a non-executive director.
Marks & Spencer rose 5.84 per cent, Carphone Warehouse gained 5.22 per cent and Old Mutual rose 4.90 per cent.
Miner Ferrexpo was down 5.96 per cent, Eurasian fell 5.60 per cent and Petrofac slid 3.65 per cent.
Energy generator Drax dropped 2.01 per cent and Vedanta Resources was down 1.98 per cent.
Anthony Grech, market analyst, at spread betting firm IG Index, explained early gains in the day were a knock-on effect of Wall Street's gains last night, while a slight recovery for oil prices aided Shell and BP.
With the FTSE 100 now getting its head above the 5500 mark, it remains to be seen whether this represents a determined surge back to the highs of May or another flash in the pan for the blue-chip index, he said.
The City may be quieter than normal with many off on holiday, but a recent lack of any devastating news appears to have given bullish investors encouragement to take advantage and nudge the FTSE into brighter territory.
He added: The effect on oil prices following recent events between Russia and Georgia could be the one to watch this week, as we see whether the 5500 mark acts as a firm platform or a plughole for the short-term FTSE.