XMMO offers a momentum take on US mid-caps culled from the S&P 400. Its index selects 80 names with the highest momentum score, derived from 12-month performance excluding the most recent month and favoring stocks with lower volatility. The index weights the names by a combination of market cap and the momentum score. Prior to June 24, 2019 the fund was quite different. It tracked a Russell growth index under a different name and ticker (PXMG).