AGG vs BND: the differences that matter

A diversified U.S. investment-grade bond core. The funds use closely related but not identical Bloomberg aggregate-bond benchmarks and sampling implementations.

Close core-bond substitutesReviewed 2026-08-25Educational research
AGG

Investment-grade U.S. bond core

0.03%stated expense ratio
BND

Investment-grade U.S. bond core

0.03%stated expense ratio
The decision in one lineThe funds use closely related but not identical Bloomberg aggregate-bond benchmarks and sampling implementations.

Side-by-side facts

Decision factorAGGBND
FundiShares Core U.S. Aggregate Bond ETFVanguard Total Bond Market ETF
IssueriSharesVanguard
Portfolio roleInvestment-grade U.S. bond coreInvestment-grade U.S. bond core
Benchmark or mandateBloomberg U.S. Aggregate Bond IndexBloomberg U.S. Aggregate Float Adjusted Index
Expense ratio0.03%0.03%
Annual fee per $10,000$3.00$3.00
Inception2003-09-222007-04-03
StructureOpen-end bond ETFOpen-end bond ETF
DistributionMonthlyMonthly
BreadthTreasuries, agencies, mortgage-backed and investment-grade corporate bondsBroad U.S. investment-grade taxable bond market
Structural risk2 / 52 / 5

A fee gap of $0.00 per $10,000 per year is only one input. Trading spreads, tracking, tax consequences and portfolio construction can outweigh it.

Atlas verdict

Duration, mortgage exposure and account logistics matter more than chasing small recent return differences. Both are broad bond cores, not cash substitutes.

When AGG has the clearer case

Investors who prefer iShares or already use AGG efficiently.

When BND has the clearer case

Investors who prefer Vanguard or already use BND efficiently.

What to monitor

What this page does not claim

This comparison does not forecast which ticker will have the higher next-month return. It separates structural choices from recent performance and leaves dynamic values out when they cannot be refreshed and dated reliably.

Primary sources

Structural facts reviewed 2026-08-25. Confirm current sponsor documents before acting.

How to make the AGG and BND decision reproducible

Compare AGG and BND by exposure, portfolio role, concentration, benchmark design, fees and implementation risk, with primary sources to verify. Begin by writing the portfolio job in one sentence. Then compare the stated objective, benchmark, holdings, structure, cost and intended portfolio role. This prevents a familiar ticker, a recent return or a small fee difference from deciding the question before the products have been defined.

Confirm that the exposures are genuinely comparable

Open each objective and benchmark description. Record the eligible universe, weighting rules, reconstitution schedule and any concentration controls. If one fund uses derivatives, options, sampling or a different legal structure, name that difference explicitly. A comparison is weak when it assumes that similar historical charts prove the portfolios are interchangeable.

Measure cost on the intended holding period

Convert each stated expense ratio into dollars for the proposed position, but do not stop there. Add the bid-ask spread, expected trading frequency, premium or discount risk, and any immediate tax cost from replacing an existing holding. For shorter periods, execution can outweigh a small annual fee gap. For longer periods, benchmark design and compounding can matter more.

Look through holdings and concentration

Compare the largest positions and their combined weight, then examine sector, country, maturity or strategy exposures that drive the result. Note whether the funds overlap with holdings already in the portfolio. A new ticker does not create diversification if it repackages the same companies or the same economic risk.

Use an adverse scenario

A correct label can still conceal a mismatch in horizon, concentration or implementation. A useful check is to test both a normal market and a condition that challenges the strategy's main assumption. Apply the same dates, return definition and distribution treatment to every fund. Include the possibility that spreads widen and that an order cannot be filled at the last displayed price.

Check the decision against current documents

Use the current prospectus, issuer disclosures, regulator material and benchmark rules. Save the document date and the exact section supporting the deciding fact. If the current source contradicts an old comparison, the current source controls. If the difference cannot be resolved, keep the uncertainty visible rather than filling it with an estimate.

Before placing an order

No single winner applies to every account. The useful conclusion states which fund fits a defined job under stated assumptions and which facts must remain true for that choice to continue making sense.