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Collateralized and Tranched Bond Structures

Fixed-income terms for auction-rate securities, collateralized bond obligations, tranches, and Z-bond structures.

Collateralized and tranched bond structures divide asset-backed or pooled-credit cash flows into classes with different payment priority, maturity, coupon, and loss exposure.

Use this branch when one collateral pool produces securities with different risk profiles.

Key Terms in This Branch

TermWhat it clarifies
Auction-Rate Securities (ARS)Securities with rates reset through auction mechanisms.
CBOCollateralized bond obligation abbreviation.
Collateralized Bond Obligation (CBO)A structured vehicle backed by a bond portfolio.
TraunchAlternate spelling of tranche in structured-finance context.
Z-BondA tranche that may defer interest or principal until earlier tranches are paid.

Common Mistakes

  • Assuming senior, mezzanine, and junior tranches respond the same way to defaults.
  • Ignoring waterfall triggers and priority rules.
  • Treating auction liquidity as permanent.
  • Comparing tranche yields without modeling timing, losses, and optionality.

In this section

Choose a subsection first. Deeper term pages live inside each subsection, which keeps large topic hubs readable.

Auction Rate Securities

Auction rate securities are long-term instruments with rates reset through periodic auctions, creating liquidity risk when auctions fail.

CBO

A CBO is a collateralized bond obligation backed by a pool of bonds and divided into tranches with different credit risk and return profiles.

Traunch

Traunch is an alternative spelling of tranche, a slice of structured finance risk with its own priority, maturity, or cash-flow claim.

Z-Bond

A Z-bond is an accrual tranche in a mortgage or structured-credit deal that defers cash payments while interest adds to principal.

Revised on Sunday, June 21, 2026