Any doubts that this is a bull-market have been quashed by the FTSE 100 putting in its best ever quarterly performance since the index's inception in 1984.After closing at 5133.90 on Wednesday, 30 September 2009, the FTSE 100 was sitting 20.82% higher than at the end of June. In points terms, the index has put on 884.69 points, topping the 815.27 (14.9%) points it put on in the final quarter of 1999 when the dot com boom was in full flow.The best performing stock in the third quarter has been recovery stock British Airways, which has risen 76.82% over the period. Before long term shareholders get too excited, however, the stock is only 6.27% above the level it was at five years ago even after the sparkling third quarter performance.The airline reported a pre-tax loss of £148m in the three months to the end of June but with signs of the recession easing speculators have been piling back into the stock on expectations that its potentially lucrative North Atlantic routes will start to see a pick-up in passenger numbers.The recovery of the mining sector is confirmed by the presence of Kazakhmys (+70.48%) at number two in the list, with Fresnillo (+48.46%) and Lonmin (+42.71%) also figuring in the top 10.The performance of Kazakhmys over a six month period is even more eye-catching; it has risen from 332.5p at the end of March to 1,074p now.'Pricing and demand for copper in the first few months of this year have been encouraging, but we will continue to focus on cash preservation and preserving the strength of the business until it is clear that international financial and commodity markets have stabilised,' said chief executive Oleg Novachuk at the end of April. Since then, the cash price for copper has risen from the mid-four thousands to just under $6,000 a tonne. Confectioner Cadbury is the third best performer, rising 55.02% on the back of the bid interest from US processed foods firm Kraft.The rising tide of the Footsie has not floated all boats, however. Defensive favourites Severn Trent and United Utilities are down 11.29% and 8.13% respectively, as income stocks fall out of fashion. The two water companies have also been under a cloud after the water regulator Ofwat outlined proposals in July on pricing over the next five years that were less generous than they hoped.Less explicable is the 6.27% decline in the share price of inter-dealer broker ICAP, which said in July that it expected underlying profit for the year to March 2010 to be in line with expectations, providing exchange rates remained at current levels for the remainder of the year. Severn Trent, United Utilities and ICAP represent the only three Footsie stocks to fall in the third quarter, though Inmarsat and Capita were not far off from joining them.