Despite the runaway rise in the Sensex, a third of the stocks are trading at almost half their 52-week highs on the Bombay Stock Exchange.In the last 60 trading days, the Sensex has gained over 1,800 points, S&P CNX Nifty 500 points and the BSE-500 and mid-cap indices by over 600 points each. However, the breadth of the market remained negative with 1,419 stocks declining against 1,221 advancing.The heavyweights were the drivers of the indices. Of the 1,800-point Sensex rally in the last 60 trading days, the top 10 stocks with a Sensex weighting of 49 per cent added 1,200 points. As these stocks are also components of the S&P CNX Nifty and the BSE-500, their contribution to these indices remained high. To the 614-point rally in the BSE-500 index, the top 25 gainers contributed almost 66 per cent.Of the 2,560 stocks traded daily on the BSE, nearly one-third or 850 stocks have been trading at 50-90 per cent discount to their 52-week highs. Another 800 stocks have been trading at a 25-50 per cent discount to their 52-week highs, while 550 stocks have been trading at 10-25 per cent discount. Overall, 86 per cent of stocks traded on the BSE are currently trading at least at 10 per cent discount to their 22-week highs while the BSE Sensex has gained over 20 per cent, Nifty and BSE-500 at around 18 per cent each.Most of the losers in the 1,800-point Sensex gain are those which are not part of either of the indices. Of the 850 stocks that have witnessed value erosion between 50 and 98 per cent, almost 60 per cent are traded under the trade-to-trade group where delivery of stocks is compulsory. Among the other group losers, 35 stocks are from the B1 group, 247 are from the B group and 86 are from the S group.Major indices are surging ahead defying the breadth of the market. For example, of the 60 trading days, the market breadth was negative for 40 trading days. During these days, the Sensex lost 1,489 points on 22 trading days and recovered by 1,307 points on 18 trading days.