U.S. large-cap stocks outperformed small-cap stocks in September for the third month in a row, according to a Russell Investment Group report. The large-cap Russell 1000 index rose 0.93% last month, compared with a 0.31% gain for the small-cap Russell 2000 index. Each of the 20 Russell benchmarks had positive returns in September, except the Russell 2000 Value index, which fell 0.17%. The Russell Midcap Value index turned in the strongest performance of any Russell index for the year with an 11.2% gain in September; midcap stocks have been strong in sectors such as health care, utilities and energy, Russell found. Additionally, the broad-market Russell 3000 index rose 0.87% in September.