Bridge Builder Core Bond Fund
Actively managed U.S. bond fund
As of its 2026 Q2 report, Bridge Builder Core Bond Fund held 5,405 positions with $28.36B in net assets. Its ten largest holdings made up 12.7% of the fund. The BBTBX share class costs 0.12% a year. Over the 12 months to May 2026, BBTBX returned 5.4%, with dividends reinvested. In 2026 Q2 it added 432 new positions and exited 289.
The investment objective of the Bridge Builder Core Bond Fund (the Fund or the Core Bond Fund) is to provide total return (capital appreciation plus income).
The fund allocates its assets across four sub-advisers, each employing distinct fixed income strategies: one uses duration-neutral security selection aligned to benchmark; another applies bottom-up value analysis across market cycles; the third pursues research-driven relative value investing in investment-grade securities; and the fourth combines top-down economic views with bottom-up security research and quantitative models. The fund invests at least 80% of assets in fixed income securities and related instruments spanning U.S. Treasuries, corporate bonds, mortgage-backed and asset-backed securities, and may also hold preferred stocks and foreign obligations. Because performance depends on each sub-adviser's security selections and sector positioning decisions, results will diverge from any single benchmark.
What you own
| Company | Weight | Value | Shares |
|---|---|---|---|
F/C US 2YR NOTE (CBT) SEP26 | 3.35% | $951.10M | — |
FIDELITY INV MMKT GOVT-INST | 2.82% | $800.29M | — |
F/C US 5YR NOTE (CBT) SEP26 | 1.56% | $441.14M | — |
US TREAS NTS 3.375% 05/15/33 3.38% · due 2033-05-15 | 0.83% | $234.95M | — |
F/C US ULTRA BOND CBT SEP26 | 0.83% | $235.22M | — |
WI TREASURY SE 4.250% 02/15/54 4.25% · due 2054-02-15 | 0.74% | $208.67M | — |
US TREAS NTS 4% 06/30/32 4.00% · due 2032-06-30 | 0.70% | $198.00M | — |
US TREAS NTS 3.5% 03/15/29 3.50% · due 2029-03-15 | 0.69% | $196.95M | — |
US TREAS NTS 4.625% 04/30/29 4.63% · due 2029-04-30 | 0.61% | $172.86M | — |
US TREAS NTS 4.5% 11/15/33 4.50% · due 2033-11-15 | 0.54% | $152.98M | — |
The 200 largest of 5,405 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Bonds | 58.57% |
| Securitized | 40.31% |
| Derivatives | 5.02% |
| Cash & short-term | 2.82% |
| Stocks | 0.01% |
These positions come to 106.73% of the fund's net assets. This counts only what the fund reported holding — the holdings disclosure covers assets, not liabilities such as borrowings — so it is not expected to reconcile to 100%.
Derivatives are shown at market value, not notional exposure.
By sector
- Securitized
- 37.1%
- Government
- 26.8%
- Other
- 15.6%
- International
- 6.2%
- 12 other sectors
- 14.2%
- Securitized
- 37.1%
- Government
- 26.8%
- Other
- 15.6%
- International
- 6.2%
- Financials
- 5.1%
- Cash
- 2.6%
- Information Technology
- 1.2%
- Health Care
- 1.0%
- Utilities
- 1.0%
- Communication Services
- 0.8%
- Industrials
- 0.8%
- Energy
- 0.7%
- Consumer Staples
- 0.3%
- Consumer Discretionary
- 0.2%
- Real Estate
- 0.2%
- Materials
- 0.1%
How it has done
BBTBX share class · total returns with dividends reinvested
Volatility over the last 12 months: 3.28%. Past returns are a record, not a forecast.
Jun 2026 has been filed since the trailing figures were struck, so it is not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.
Fees & fund details
Bridge Builder Core Bond Fund is an actively managed U.S. bond fund.
- Asset class
- Bonds
- Region
- United States
- Management
- Actively managed
- Fund type
- Open-end fund
- Credit quality
- Investment grade
- Rate sensitivity
- Intermediate duration
- Expense ratio, by class
- 0.12%· BBTBX 0.12%
- Portfolio turnover
- 125.00% a year · as of 2025 Q4
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Turnover is how much of the portfolio was replaced in a year.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
432 new· the largest 8
289 exited· the largest 8
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-06-30
Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.
| Fixed rate | 82.3% |
| Floating rate | 17.7% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 1.6% |
| 1-3y | 11.4% |
| 3-5y | 13.3% |
| 5-10y | 22.6% |
| 10y+ | 51.1% |
These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.
Risk profile
Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2
Most of this fund’s sensitivity is to interest rates, with credit spreads carrying about half as much.
Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.
| Interest rates | 64% |
| Credit spreads | 36% |
Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.
Share of the fund's spread duration carried by each credit tier.
| Investment grade | +3.33 yr |
| High yield | +0.00 yr |
Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.
| 3 mo | 0.23 yr | 4% |
| 1 yr | 0.36 yr | 6% |
| 5 yr | 1.54 yr | 26% |
| 10 yr | 2.47 yr | 42% |
| 30 yr | 1.29 yr | 22% |
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.27 yr | 8% |
| 5 yr | 1.13 yr | 34% |
| 10 yr | 1.52 yr | 46% |
| 30 yr | 0.40 yr | 12% |
The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.
Show the numbers
| Tenor | Rate yrs | IG yrs | HY yrs | IG $/bp | HY $/bp |
|---|---|---|---|---|---|
| 3 mo | +0.23 | +0.01 | +0.00 | $34.4k | $128 |
| 1 yr | +0.36 | +0.27 | +0.00 | $753.3k | $2.3k |
| 5 yr | +1.54 | +1.13 | +0.00 | $3.21m | $4.7k |
| 10 yr | +2.47 | +1.52 | +0.00 | $4.32m | $3.7k |
| 30 yr | +1.29 | +0.40 | +0.00 | $1.13m | $1.5k |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Understand how this fund fits with the rest.
Explore shared holdings, compare funds and follow their businesses with your connected AI:
- “Where do my funds overlap — BBTBX, QQQ and the fund in my 401(k)?”
- “How do this fund’s ten biggest holdings stack up against each other?”
- “For my target-date fund, what’s the real stock-and-bond mix once you look through it?”