Sinking Fund

IntermediateBonds & Fixed Income2 min read

Quick Definition

A provision requiring the bond issuer to set aside money periodically to retire a portion of the debt before maturity.

Key Takeaways

  • Requires periodic retirement of a portion of outstanding bonds
  • Issuer can buy in the open market or call by lottery at par
  • Reduces credit risk by preventing large balloon payments
  • May create reinvestment risk if bonds are called at par above market

What Is Sinking Fund?

A sinking fund is a bond indenture provision that requires the issuer to retire a specified portion of the outstanding bonds at regular intervals, typically annually, before the final maturity date. The issuer can satisfy the sinking fund requirement by either purchasing bonds in the open market (if trading below par) or calling bonds at par via a lottery. Sinking funds reduce credit risk for bondholders by ensuring the issuer does not face a large "balloon" payment at maturity, gradually reducing the outstanding debt burden. However, they also introduce reinvestment risk — particularly the lottery call feature, which may force investors to give up bonds at par when market prices are higher. Sinking funds are most common in corporate bonds.

Sinking Fund Example

  • 1A $500 million bond issue with a sinking fund might require the company to retire $50 million annually starting in year 5
  • 2If a bond trades at 105 ($1,050), the issuer would buy bonds in the open market rather than calling at par ($1,000) — but if it trades at 95, they'd call at par