Mfs Investment Management is an SEC registered investment adviser organized as a corporation with a primary office location in Boston, MA. Its latest Form ADV filing, dated March 31, 2026, reports $514.1B in regulatory assets under management, 1,244 employees, and 355 accounts.
Portfolio management for pooled investment vehicles
Fee models offered
2 types reported
Asset based fees
Other fee arrangements
Sources checked May 13, 2026
Client Coverage Demographics
Top client segmentInvestment Cos. represent 52.7% of total clients.
Top client categories% of clientsClients
1
Investment Cos.
52.7%
187
2
Pooled Investment Vehicles
32.4%
115
3
Corporations
7.3%
26
4
Pension Plans
5.1%
18
5
Sovereign Wealth
1.1%
4
Regulatory Assets Under Management Breakdown
Total regulatory assets under management$514.1Bas of March 31, 2026
Discretionary92.8%
$476.8B
93% of total RAUM92.8%
Non-discretionary7.2%
$37.2B
7% of total RAUM7.2%
Regulatory assets under management are split between discretionary and non-discretionary assets.
Assets under management Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Latest AUM$514.1B
Total Accounts355
10Y AUM Change+$210.8B (+69.5%)
Employee Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Total Employees1,244
Clients per Employee0:1
10Y Employee Change+244 (+24.4%)
* Metrics are based on the latest available data, including Form ADV filings, brochures, and relationship summaries pulled from the SEC IAPD, and may be subject to change. Learn what is included in the Rialytix data. Please refer to the firm's official disclosures for the most accurate information using their CRD number. This is not investment advice.