Investing · ETF deep dive
ZDB BMO Discount Bond Index ETF
The taxable-account bond fund: aggregate exposure built from low-coupon bonds, so less of the return arrives as fully-taxed interest.
Best for: Investors holding bonds in a non-registered account — the one place the other aggregates actively hurt
Pros
- BMO’s stated screen: coupons ≤ 1.4× the bond’s YTM — forcing discount bonds
- Distribution yield 1.74% vs YTM 3.52% — the gap IS the tax shelter
- Same duration (6.91) and sector shape as ZAG, at 0.10%
Cons
- Concentrated: 325 bonds, with one GoC issue at 13.8% of the fund
- Pointless inside a TFSA/RRSP — you’d be paying for tax design you can’t use
- Lower YTM (3.52%) than the plain aggregates — the screen has a price
What's inside ZDB
| Underlying fund | Weight |
|---|---|
| Credit quality: AAA 44.0% · AA 29.2% · A 20.0% · BBB 6.8% | 100.0% |
| Largest single bond: Gov of Canada 0.50% 12/2030 | 13.8% |
Federal 43.6% · Provincial 30.5% · Corporate 24.3% — aggregate-shaped, tax-screened (Provider sector table, Jun 9, 2026) · holdings as of June 9, 2026 (325 bonds)
The deep dive
Bond interest is the worst-taxed income in Canada, which makes a regular aggregate a poor citizen of a non-registered account. ZDB’s answer, in BMO’s own words: it “invests in bonds with a coupon rate equal or less than 1.4 times the yield to maturity” — i.e., discount bonds, where more of the return arrives as price appreciation toward par rather than as coupons. The visible result: a 1.74% distribution yield against a 3.52% YTM. The missing 1.8 points isn’t gone — it accrues in the price, taxed more gently when realized.
Costs of the design: a thinner portfolio (325 bonds vs ZAG’s 1,852, with one 2030 GoC issue at 13.8%), and a YTM about 15bps under the plain aggregate. Worth it where taxes bite; wasted where they don’t. The other taxable-account approach — swap-based total-return funds like HBB — solves the same problem differently and deserves its own future page.
The rest of the field
The rest of the field, one line each:
- ZAG — the $12.8B aggregate, 0.09% MER
- XBB — same index as ZAG, since 2000
- VAB — Bloomberg float-adjusted aggregate
- VSB — short-term (2.7yr duration)
- XSB — short-term (2.8yr duration), since 2000
- ZFL — long federal — 17yr duration, the rate bet
Frequently asked questions
What does ZDB hold?
ZDB holds 325 low-coupon investment-grade Canadian bonds — led by Credit quality: AAA 44.0% · AA 29.2% · A 20.0% · BBB 6.8% at 100.0%, Largest single bond: Gov of Canada 0.50% 12/2030 at 13.8% (as of June 9, 2026 (325 bonds)). Credit and sector mix: Federal 43.6% · Provincial 30.5% · Corporate 24.3% — aggregate-shaped, tax-screened (provider sector table, jun 9, 2026). Weights drift between rebalances — ftse canada universe discount bond index — coupons capped at 1.4× ytm · duration 6.91 yrs.
What does ZDB cost?
Currently 0.09% management fee; 0.10% published MER (page as of Jun 9, 2026). Canadian aggregate bond ETFs now cost just 0.09%–0.10% — specialty rungs more (ZFL 0.22%) — see the full comparison. At bond-level expected returns, every basis point matters: the MER calculator shows why.
Which account should hold ZDB — and should it be a GIC instead?
Bond interest is fully taxed at your marginal rate, the least favourable treatment there is — so bond ETFs belong in an RRSP, RRIF or TFSA first (the deliberate exception is ZDB, engineered for taxable accounts). And before buying any bond fund for dated money, run the honest comparison: our live GIC table often pays more than a bond ETF's YTM with zero price risk — the fund's advantages are daily liquidity and gains if rates fall. The bonds guide walks the full decision.
The bottom line
In a taxable account, the most thoughtfully engineered bond fund in Canada. Anywhere else, just buy ZAG. The placement logic lives in our asset-location guide.
This page is for educational purposes only and is not investment advice. Fund facts were verified at BMO ETFs's published fact sheets and product pages on June 10, 2026; holdings and weights are point-in-time and drift between rebalances; published MERs may lag recent fee changes (page as of Jun 9, 2026). We deliberately do not compare or project returns. Read the fund facts document before buying. See our methodology.