The S&P/ASX300 price index has struggled to breach 6,000 since its 2007 peak, exceeding 5,900 in March 2015 and again this week. It hasn't been below 5,600 since February this year. The range-bound index is dominated by a handful of companies in out-of-favour sectors, and it disguises the big share price winners which are too small to move the index higher.