Getty Images The smaller the company, the better the returnMuch has been made about the outperformance of small-capitalization stocks as fears about global trade have intensified, but a subset of small-cap equities has produced even more stellar results this year. The Russell Microcap Index RUMIC, -1.19% which is a benchmark of companies with an average market value of about $730 million, has gained 14% so far in 2018, as of Wednesday’s close, that compares with a year-to-date advance of 11.1% for the Russell 2000 index RUT, -1.06% which has a roster of companies with an average market value of $2.6 billion. Both are trading in record territory, with the Russell Microcap putting in a 24th all-time high for 2018. That is one more record than the Russell 2000, as of Wednesday.via