MML VIP Fidelity Institutional AM Core Plus Bond Fund
MML SERIES INVESTMENT FUND
Expense ratio
Net assets1
$361.66M
Holdings1
983
Category
Taxable Bond
Return

Investment objective & strategy

As of Nov. 14, 2025 · prospectus

Objective. The Fund seeks a high level of current income.

Strategy. Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in a diversified portfolio of investment grade fixed income securities (rated Baa3 or higher by Moodys, BBB- or higher by Standard & Poors, BBB- or higher by Fitch, or A-2 by S&P, P-2 by Moodys, or F-2 by Fitch for short-term debt obligations, or, if unrated, determined by the Funds subadviser, FIAM LLC (FIAM), to be of comparable quality). The Fund allocates its assets across investment grade, high yield, and emerging markets debt securities. The Funds investment strategy is referred to as Core Plus because, in addition to investing in a core portfolio of investment grade debt securities, … Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in a diversified portfolio of investment grade fixed income securities (rated Baa3 or higher by Moodys, BBB- or higher by Standard & Poors, BBB- or higher by Fitch, or A-2 by S&P, P-2 by Moodys, or F-2 by Fitch for short-term debt obligations, or, if unrated, determined by the Funds subadviser, FIAM LLC (FIAM), to be of comparable quality). The Fund allocates its assets across investment grade, high yield, and emerging markets debt securities. The Funds investment strategy is referred to as Core Plus because, in addition to investing in a core portfolio of investment grade debt securities, FIAM normally invests a portion of the Funds assets in below investment grade debt securities and/or emerging markets debt securities. The Fund may invest up to 20% of its net assets in below investment grade debt securities (junk or high yield bonds), including bank loans. In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if FIAM considers doing so would be consistent with the Funds investment objective. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. The Funds assets may be invested in securities of foreign issuers, including emerging markets, in addition to securities of domestic issuers. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low-to middle-income economies as classified by the World Bank, and other countries or markets that FIAM identifies as having similar emerging markets characteristics. Emerging markets tend to have relatively low gross national product per capita compared to the worlds major economies and may have the potential for rapid economic growth. The Fund may enter into repurchase agreement transactions. The Fund may at times have significant exposure to one or more industries or sectors. The Fund may hold a portion of its assets in cash or cash equivalents. The Fund may purchase and sell securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis, and may enter into dollar roll or reverse repurchase agreement transactions. The Fund may also invest in collateralized loan obligations. In pursuing its investment objective, the Fund may (but is not obligated to) invest a significant portion of its assets in a wide variety of exchange-traded and over-the-counter derivatives, including, but not limited to, interest rate swaps, total return swaps, credit default swaps, options (including options on futures and swaps), forwards, and futures contracts (both long and short positions) on securities, other instruments, indexes, or currencies. Depending on FIAMs outlook and market conditions, the Fund may engage in these transactions to increase or decrease its exposure to changing security prices, interest rates, credit qualities, foreign exchange rates, or other factors that affect security values, or to gain or reduce exposure to an asset, instrument, currency, or index. Use of derivatives by the Fund may create investment leverage. FIAM uses the Bloomberg U.S. Aggregate Bond Index (the Index) as a guide in structuring the Fund and selecting its investments. FIAM manages the Fund to have similar overall interest rate risk to the Index. FIAM intends for the Funds portfolio dollar-weighted average duration generally to match (within 10%) the average duration of the Index (as of June 30, 2025, the average duration of the Index was 6.06 years). Duration measures the price sensitivity of a bond to changes in interest rates. Duration is the dollar weighted average time to maturity of a bond utilizing the present value of all future cash flows. FIAM considers other factors when selecting the Funds investments, including the credit quality of the issuer, security-specific features, current valuation relative to alternatives in the market, short-term trading opportunities resulting from market inefficiencies, and potential future valuation. In managing the Funds exposure to various risks, including interest rate risk, FIAM considers, among other things, the markets overall risk characteristics, the markets current pricing of those risks, and internal views of potential future market conditions. FIAM allocates the Funds assets among different asset classes using the composition of the Index as a guide, and among different market sectors (for example, corporate, asset-backed, or government securities) and different maturities based on its view of the relative value of each sector or maturity. In selecting foreign securities, FIAMs analysis also considers the credit, currency, and economic risks associated with the security and the country of its issuer. FIAM may also consider an issuers potential for success in light of its current financial condition, its industry position, and economic and market conditions. To earn additional income for the Fund, FIAM may use a trading strategy that involves selling (or buying) mortgage securities and simultaneously agreeing to purchase (or sell) mortgage securities on a later date at a set price. The Fund expects that it will engage in active and frequent trading and so will typically have a relatively high portfolio turnover rate.

Top holdings

As of March 31, 2026 · N-PORT
SecurityTickerValue% of fund
US TREASURY N/B $44.66M 12.35%
US TREASURY N/B $37.28M 10.31%
US TREASURY N/B $31.92M 8.83%
US TREASURY N/B $12.88M 3.56%
US TREASURY N/B $9.73M 2.69%
US TREASURY N/B $9.50M 2.63%
US TREASURY N/B $9.48M 2.62%
US TREASURY N/B $9.38M 2.59%
Government National Mortgage Association, TBA GNR $6.27M 1.73%
FIXED INC CLEARING CORP.REPO $5.54M 1.53%
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Allocation by sector

As of March 31, 2026 · N-PORT
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Portfolio moves

Dec 31, 2025 → Mar 31, 2026
Opened
184
Exited
70
Increased
37
Decreased
137
Unchanged
625

How many positions this fund opened, exited, grew, trimmed, or left unchanged between its two most recent N-PORT snapshots — net changes between point-in-time reports, not a trade log.

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Advisers

As of December 31, 2025 · N-CEN
FirmRole
MML Investment Advisers, LLC Adviser
FIAM LLC Sub-adviser

Footnotes

  1. Net assets and holdings count as of March 31, 2026, from the fund's N-PORT filing.

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