MFS Mid Cap Growth Fund - Class I (OTCIX)

The MFS Mid Cap Growth I fund primarily focuses its investments, dedicating a minimum of 80% of its net assets, to companies with medium market capitalizations. MFS typically defines these mid-cap entities as firms whose market values are comparable to those included in the Russell Midcap® Growth Index, based on their capitalization over the 13 months leading up to the time of purchase.