BBMUX
Bridge Builder Municipal Bond Fund
Bridge Builder Trust
Expense ratio1
0.12%
Net assets2
$20.14B
Holdings2
5722
Category
Muni Bond
2025 return3
5.09%

Investment objective & strategy

As of Oct. 27, 2025 · prospectus

Objective. The investment objective of the Bridge Builder Municipal Bond Fund (the Fund or the Municipal Bond Fund) is to provide current income exempt from federal tax,

Strategy. The Fund invests, under normal market conditions, at least 80% of its net assets (plus the amount of borrowings for investment purposes) in municipal securities of any maturity or duration whose interest is exempt from federal income tax. These municipal securities include debt obligations issued by or on behalf of a state or local entity or other qualifying issuer that pay interest that is, in the opinion of bond counsel to the issuer, generally excludable from gross income for federal income tax purposes (except that the interest may be includable in taxable income for certain taxpayers subject to the federal alternative minimum tax (Federal AMT)). Municipal securities may be obligations of a variety of issuers, including state or local entities … The Fund invests, under normal market conditions, at least 80% of its net assets (plus the amount of borrowings for investment purposes) in municipal securities of any maturity or duration whose interest is exempt from federal income tax. These municipal securities include debt obligations issued by or on behalf of a state or local entity or other qualifying issuer that pay interest that is, in the opinion of bond counsel to the issuer, generally excludable from gross income for federal income tax purposes (except that the interest may be includable in taxable income for certain taxpayers subject to the federal alternative minimum tax (Federal AMT)). Municipal securities may be obligations of a variety of issuers, including state or local entities or other qualifying issuers. Issuers may be states, territories, and possessions of the United States and the District of Columbia and their political subdivisions, agencies, and instrumentalities. The Fund invests in municipal securities financing projects, including but not limited to those relating to education, health care, and transportation. The Fund may invest in municipal securities rated below investment grade, also known as junk bonds, or in unrated municipal securities that a sub-adviser of the Fund believes are of comparable quality. Investment grade securities are those securities that are rated at or above Baa3 by Moodys Investors Service, Inc. (Moodys), BBB- by Standard & Poors Corporation (S&P) or Fitch Ratings (Fitch), or an equivalent rating by another nationally recognized securities rating organization (NRSRO), or securities that are unrated but deemed by the sub-adviser to be comparable in quality to instruments that are so rated. If a security is rated differently by multiple NRSROs, the Fund treats the security as being rated in the highest rating category received from an NRSRO. The Fund may invest in zero coupon bonds, which are issued at substantial discounts from their value at maturity and pay no cash income to their holders until they mature. The Fund may purchase or sell securities which it is eligible to purchase or sell on a when-issued and delayed-delivery basis and may make contracts to purchase or sell such securities for a fixed price at a future date beyond normal settlement time (forward commitments). The purchase or sale of securities on a when-issued basis or on a delayed delivery basis or through a forward commitment involves the purchase or sale of securities by the Fund at an established price with payment and delivery taking place in the future. The Fund also invests in U.S. Treasury futures and may buy or sell futures to hedge exposure to risk factors, for speculative purposes or as a substitute for investing in conventional fixed income securities. In addition, the Fund may invest in privately issued securities (e.g., Rule 144A securities) and other investment companies, including open-end or closed-end investment companies and exchange-traded funds (ETFs) that have characteristics that are consistent with the Funds investment objective. The Funds portfolio is constructed by combining the investment styles and strategies of multiple sub-advisers that have been or will be retained by the Adviser (each a Sub-adviser). Each Sub-adviser may use both its own proprietary and external research and securities selection processes to manage its allocated portion of the Funds assets. Portfolio securities may be sold at any time. Sales may occur when a Sub-adviser seeks to take advantage of what a Sub-adviser considers to be a better investment opportunity, when a Sub-adviser believes the portfolio securities no longer represent relatively attractive investment opportunities, when a Sub-adviser perceives deterioration in the credit fundamentals of the issuer, or when a Sub-adviser believes that it would be appropriate to do so in order to readjust the duration or asset allocation of its portion of the Funds investment portfolio. The Adviser is responsible for determining the amount of Fund assets allocated to each Sub-adviser. The Adviser allocates Fund assets to the following Sub-advisers: Robert W. Baird & Co. Incorporated (Baird), BlackRock Investment Management, LLC (BlackRock), FIAM LLC (FIAM), and MacKay Shields LLC (MacKay Shields). The Adviser may adjust allocations to the Sub-advisers at any time or make recommendations to the Board with respect to the hiring, termination, or replacement of a Sub-adviser. Below is a summary of each Sub-advisers principal investment strategies. Bairds Principal Investment Strategies The foundation of Bairds strategy is a focus on seeking to control risk. With the belief that the bond market is efficient over time in discounting interest rate risk, making interest rate timing extremely difficult to consistently forecast over time, a key tenet of Bairds strategy is to manage its allocated portion of the Fund on a duration-neutral basis relative to its selected benchmark, the Bloomberg Municipal Bond Index (with maturities ranging from 1 30 years). Baird then seeks to add incremental return on a consistent basis through an in-depth, research-driven approach, identifying and capturing relative value opportunities in less efficient areas of the market. These include positioning along the yield curve on a duration-neutral basis overall, credit, sector, and subsector weightings all relative to the benchmark while also focusing on security selection and efficient trade execution. Typically, Bairds strategy also seeks to have an income advantage relative to the benchmark as a means of adding incremental return. BlackRocks Principal Investment Strategies BlackRock takes a top-down, bottom-up approach with a flexible investment framework in managing its allocated portion of the Funds assets. The investment process begins with setting a macro-outlook and broad strategy guidelines around credit, duration, yield curve, structure, and liquidity. Portfolio management works closely with BlackRocks credit research team to determine which sectors of the municipal market provide the most value and should be overweight and which should be underweight. Once a sector view is established, BlackRocks credit research team works to identify securities that provide the best risk reward profile. BlackRocks security selection process is based on its relative value outlook and the quantitative assessment of the security and portfolio. In managing its allocated portion of the Funds assets, BlackRock seeks total return derived primarily from coupon interest, and secondarily, capital appreciation. FIAMs Principal Investment Strategies FIAM uses a municipal bond index as a guide in structuring and selecting its investments for its allocated portion of the Funds assets. This municipal bond index represents FIAMs view of how the portfolios competitive universe will perform over time. This index is a market value-weighted index of short to intermediate investment-grade fixed-rate municipal bonds. FIAM considers a variety of factors when selecting investments, including the credit quality of issuers, security-specific features, current valuations relative to alternatives in the market, short-term trading opportunities resulting from market inefficiencies, and potential future valuations. In managing the portfolios exposure to various risks, including interest rate risk, FIAM also considers the markets overall risk characteristics, current pricing of those risks, and internal views of potential future market conditions. MacKay Shields Principal Investment Strategies MacKay Shields relative-value investment strategy combines a top-down macro view with bottom-up credit research driven security selection. MacKay Shields investment discipline begins by outlining a macro view of the economy, interest rates, inflation and both national and regional political concerns. The top-down component guides decisions relating to the Funds credit distribution, sector distribution, state exposure and yield curve positioning. The investment strategy seeks to maintain duration neutrality, typically expressed as a range around the duration of the relevant benchmark. MacKay Shields approach is driven by fundamental bottom-up security analysis using deep credit research and spread analysis. In doing so, the investment process seeks to identify mispricings and opportunities for total return with an emphasis and focus on risk management.

Allocation by sector

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

Dec 31, 2025 → Mar 31, 2026
Opened
355
Exited
182
Increased
38
Decreased
192
Unchanged
5139

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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NYLI MacKay Strategic Muni Allocation Fund · MTFHX, MTFEX, MTFDX, MTFGX, MTFFX, MTFMX, MTFZX 19% 0.45%
Fidelity Intermediate Municipal Income Fund · FLTMX, FZIAX, FZICX, FZITX, FZIIX, FIQZX 17% 0.31%
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Advisers

As of June 30, 2025 · N-CEN
FirmRole
BlackRock Investment Management, LLC Sub-adviser
Robert W. Baird & Co. Incorporated Sub-adviser
FIAM LLC Sub-adviser
MacKay Shields LLC Sub-adviser
OLIVE STREET INVESTMENT ADVISERS LLC Adviser

Footnotes

  1. Expense ratio as of October 27, 2025, from the fund's prospectus.
  2. Net assets and holdings count as of March 31, 2026, from the fund's N-PORT filing.
  3. Total return for calendar year 2025, before tax and after fund expenses. Computed by compounding the twelve monthly total returns the fund reported in its SEC N-PORT filings for 2025 (the latest prospectus does not yet chart this year).

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