MFS Series Trust X
02/26/2026 | Press release | Distributed by Public on 02/26/2026 08:03
Prospectus by Investment Company (Form 497)
SUPPLEMENT TO THE STATEMENT OF ADDITIONAL INFORMATION
The date of this supplement is February 26, 2026.
For the MFS® Funds listed below:
|
MFS® AGGRESSIVE GROWTH ALLOCATION FUND |
MFS® GROWTH ALLOCATION FUND |
|
MFS® BLENDED RESEARCH® GROWTH EQUITY FUND |
MFS® INTERNATIONAL DIVERSIFICATION FUND |
|
MFS® BLENDED RESEARCH® MID CAP EQUITY FUND |
MFS® INTERNATIONAL GROWTH FUND |
|
MFS® BLENDED RESEARCH® SMALL CAP EQUITY FUND |
MFS® INTERNATIONAL INTRINSIC VALUE FUND |
|
MFS® BLENDED RESEARCH® VALUE EQUITY FUND |
MFS® INTERNATIONAL LARGE CAP VALUE FUND |
|
MFS® CONSERVATIVE ALLOCATION FUND |
MFS® MANAGED WEALTH FUND |
|
MFS® EMERGING MARKETS EQUITY FUND |
MFS® MODERATE ALLOCATION FUND |
Effective immediately, the sub-sections entitled "Compensation," "Ownership of Fund Shares," and "Other Accounts" under the main heading entitled "APPENDIX D - PORTFOLIO MANAGER(S)" are hereby restated, with respect to MFS Blended Research Growth Equity Fund, MFS Blended Research Mid Cap Equity Fund, MFS Blended Research Small Cap Equity Fund, and MFS Blended Research Value Equity Fund only, as follows:
Compensation
MFS' philosophy is to align portfolio manager compensation with the goal to provide shareholders with long-term value through a collaborative investment process. Therefore, MFS uses long-term investment performance as well as contribution to the overall investment process and collaborative culture as key factors in determining portfolio manager compensation. In addition, MFS seeks to maintain total compensation programs that are competitive in the asset management industry in each geographic market where it has employees. MFS uses competitive compensation data to ensure that compensation practices are aligned with its goals of attracting, retaining, and motivating the highest-quality professionals.
MFS reviews portfolio manager compensation annually. In determining portfolio manager compensation, MFS uses quantitative means and qualitative means to help ensure a durable investment process. As of December 31, 2025, portfolio manager total cash compensation is a combination of base salary and performance bonus:
Base Salary - Base salary generally represents a smaller percentage of portfolio manager total cash compensation than performance bonus.
Performance Bonus - Generally, the performance bonus represents more than a majority of portfolio manager total cash compensation.
The performance bonus is based on a combination of quantitative and qualitative factors, generally with more weight given to the former and less weight given to the latter. The quantitative portion is primarily based on the pre-tax performance of accounts managed by the portfolio manager over a range of fixed-length time periods, intended to provide the ability to assess performance over time periods consistent with a full market cycle and a strategy's investment horizon. The fixed-length time periods include the portfolio manager's full tenure on each Fund/strategy and, when available, 10-, 5-, and 3-year periods. For portfolio managers who have served for less than three years, shorter-term periods, including the one-year period, will also be considered, as will performance in previous roles, if any, held at the firm. Emphasis is generally placed on longer performance periods when multiple performance periods are available. Performance is evaluated across the full set of strategies and portfolios managed by a given portfolio manager, relative to appropriate peer group universes and/or representative indices ("benchmarks"). As of December 31, 2025, the following benchmarks were used to measure the following portfolio managers' performance for the following Funds, and/or MFS Funds managed in a substantially similar strategy to the portion of the Funds managed by the portfolio managers, unless otherwise indicated:
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Benchmark(s) |
|
MFS Blended Research Growth Equity Fund |
Matt Krummell |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds Morningstar US Large Growth |
|
Nathan Bryant1 |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds |
|
|
Jim Fallon |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds |
|
|
Jonathan Sage |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds |
|
|
Jed Stocks |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds |
|
|
Jenney Zhang1 |
Russell 1000® Growth Index Lipper Large-Cap Growth Funds |
|
|
MFS Blended Research Mid Cap Equity Fund |
Matt Krummell |
Russell Midcap® Index Lipper Mid-Cap Core Funds Morningstar US Mid-Cap Blend |
|
Nathan Bryant1 |
Russell Midcap® Index Lipper Mid-Cap Core Funds |
|
|
Jim Fallon |
Russell Midcap® Index Lipper Mid-Cap Core Funds |
|
|
Jonathan Sage |
Russell Midcap® Index Lipper Mid-Cap Core Funds |
|
|
Jed Stocks |
Russell Midcap® Index Lipper Mid-Cap Core Funds |
|
|
Jenney Zhang1 |
Russell Midcap® Index Lipper Mid-Cap Core Funds |
|
|
MFS Blended Research Small Cap Equity Fund |
Matt Krummell |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
Nathan Bryant1 |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
|
Jim Fallon |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
|
Jonathan Sage |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
|
Jed Stocks |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
|
Jenney Zhang1 |
Russell 2000® Index Lipper Small-Cap Core Funds |
|
|
MFS Blended Research Value Equity Fund |
Jonathan Sage |
Russell 1000® Value Index Lipper Large-Cap Value Funds
Lipper Multi-Cap Value Funds |
|
Nathan Bryant1 |
Russell 1000® Value Index Lipper Multi-Cap Value Funds |
|
|
Jim Fallon |
Russell 1000® Value Index Lipper Multi-Cap Value Funds |
|
|
Matt Krummell |
Russell 1000® Value Index Lipper Multi-Cap Value Funds |
|
|
Jed Stocks |
Russell 1000® Value Index Lipper Multi-Cap Value Funds |
|
|
Jenney Zhang1 |
Russell 1000® Value Index Lipper Multi-Cap Value Funds |
|
1 Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 1, 2026.
Benchmarks may include versions and components of indices, custom indices, and linked indices that combine performance of different indices for different portions of the time period, where appropriate.
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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The qualitative portion is based on the results of an annual internal peer review process (where portfolio managers are evaluated by other portfolio managers, analysts, and traders) and management's assessment of overall portfolio manager contributions to the MFS investment process and the client experience (distinct from fund and other account performance).
The performance bonus may be in the form of cash and/or a deferred cash award, at the discretion of management. A deferred cash award is issued for a cash value and becomes payable over a three-year vesting period if the portfolio manager remains in the continuous employ of MFS or its affiliates. During the vesting period, the value of the unfunded deferred cash award will fluctuate as though the portfolio manager had invested the cash value of the award in an MFS fund(s) selected by the portfolio manager. A selected fund may, but is not required to, be a fund that is managed by the portfolio manager.
MFS Equity Plan - Portfolio managers also typically benefit from the opportunity to participate in the MFS Equity Plan. Equity interests are awarded by management, on a discretionary basis, taking into account tenure at MFS, contribution to the investment process, and other factors.
Finally, portfolio managers also participate in benefit plans (including a defined contribution plan and health and other insurance plans) and programs available generally to other employees of MFS. The percentage such benefits represent of any portfolio manager's compensation depends upon the length of the individual's tenure at MFS and salary level, as well as other factors.
Ownership of Fund Shares
The following table shows the dollar range of equity securities of the Fund beneficially owned by the Fund's portfolio manager(s) (including the value of any deferred cash award which is based on the performance of the Fund) as of the Fund's fiscal year ended May 31, 2025, unless otherwise indicated. The following dollar ranges apply:
N. None
A. $1 - $10,000
B. $10,001 - $50,000
C. $50,001 - $100,000
D. $100,001 - $500,000
E. $500,001 - $1,000,000
F. Over $1,000,000
|
Fund |
Portfolio Manager |
Dollar Range of Equity Securities in the Fund |
|
MFS Blended Research Growth Equity Fund |
Matt Krummell |
N |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Jonathan Sage |
N |
|
|
Jed Stocks |
N |
|
|
Jenney Zhang1 |
N |
|
|
MFS Blended Research Mid Cap Equity Fund |
Matt Krummell |
N |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Jonathan Sage |
N |
|
|
Jed Stocks |
N |
|
|
Jenney Zhang1 |
N |
|
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Dollar Range of Equity Securities in the Fund |
|
MFS Blended Research Small Cap Equity Fund |
Matt Krummell |
N |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Jonathan Sage |
N |
|
|
Jed Stocks |
N |
|
|
Jenney Zhang1 |
N |
|
|
MFS Blended Research Value Equity Fund |
Jonathan Sage |
D |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Matt Krummell |
N |
|
|
Jed Stocks |
N |
|
|
Jenney Zhang1 |
N |
|
1 Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 31, 2026.
Other Accounts
In addition to the Fund, each portfolio manager of the Fund is named as a portfolio manager of certain other accounts managed or sub-advised by MFS or an affiliate. Wholly-owned subsidiaries of registered investment companies are not considered separate accounts for purposes of number of accounts and total assets managed. The number and assets of these accounts were as follows as of the Fund's fiscal year ended May 31, 2025, unless otherwise indicated:
|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
MFS Blended Research Growth Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$8.1 billion |
|
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
29 |
$8.0 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
28 |
$8.5 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
15 |
$4.0 billion |
|||
|
Other Accounts |
31 |
$11.3 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
25 |
$8.0 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
MFS Blended Research Mid Cap Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$8.1 billion |
|
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
29 |
$8.0 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
28 |
$8.5 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
15 |
$4.0 billion |
|||
|
Other Accounts |
31 |
$11.3 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
25 |
$8.0 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
MFS Blended Research Small Cap Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$8.1 billion |
|
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
29 |
$8.0 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
28 |
$8.5 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
15 |
$4.0 billion |
|||
|
Other Accounts |
31 |
$11.3 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
25 |
$8.0 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
MFS Blended Research Value Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$8.1 billion |
|
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
29 |
$8.0 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
28 |
$8.5 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
15 |
$4.0 billion |
|||
|
Other Accounts |
31 |
$11.3 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$7.9 billion |
||
|
Other Pooled Investment Vehicles |
13 |
$2.6 billion |
|||
|
Other Accounts |
25 |
$8.0 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
1 |
Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 31, 2026. |
||||
|
2 |
Includes the Fund. |
||||
Advisory fees were not based upon performance of any of the accounts identified in the table above.
SEPTEMBER-SAI-COMBINED-SUP-I-022626
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MFS Series Trust X published this content on February 26, 2026, and is solely responsible for the information contained herein. Distributed via EDGAR on February 26, 2026 at 14:03 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]