Convertible Preferred: Advanced Concepts

You learned the basics of convertible preferred in the types section. Now let's cover the advanced concepts the exam tests: anti-dilution adjustments and sinking fund provisions.


Anti-Dilution Agreement (Covenant)

Virtually all convertible preferred stock is issued with an anti-dilution covenant that protects holders from dilution caused by stock splits and stock dividends.

  • When a stock split or stock dividend occurs, the conversion ratio is adjusted proportionally
  • Without anti-dilution protection, a 2-for-1 split would halve the value of the conversion feature
  • The anti-dilution adjustment protects the holder, not the issuer

How the Adjustment Works

After a stock split:

  • The conversion ratio increases (more shares received)
  • The conversion price decreases (lower price per share)
  • The conversion value stays the same before and after the split

Worked Example

Original terms: $100 par, conversion price $50, conversion ratio = 2 shares

After a 2-for-1 stock split:

  • New conversion price: $50 / 2 = $25
  • New conversion ratio: $100 / $25 = 4 shares (or simply 2 x 2 = 4)
  • If common was at $50 pre-split and $25 post-split:
    • Pre-split conversion value: 2 x $50 = $100
    • Post-split conversion value: 4 x $25 = $100
    • Conversion value is unchanged - the holder is protected

Another Example: 3-for-1 Split

Original: $100 par, conversion price $30, conversion ratio = 3.33 shares

After 3-for-1 split:

  • New conversion price: $30 / 3 = $10
  • New conversion ratio: $100 / $10 = 10 shares

Exam Tip: Gotchas

  • Anti-dilution adjustments protect the HOLDER, not the issuer.
  • After a stock split, the conversion ratio increases and the conversion price decreases proportionally.
  • The exam may give you a pre-split conversion ratio and ask for the post-split ratio; just multiply the ratio by the split factor.

Sinking Fund Provisions

Some preferred stock issues include a sinking fund requiring the issuer to retire a portion of outstanding shares each year.

  • The issuer sets aside money periodically to repurchase shares on the open market or call them at a specified price
  • Sinking funds reduce risk for the investor by ensuring the issuer systematically retires the obligation
  • Works the same way as sinking funds on bonds

How Sinking Funds Affect the Investor

FactorImpact
Credit riskReduced (issuer is gradually retiring the obligation)
LiquidityReduced (fewer shares outstanding over time)
Call riskIncreased (issuer may call specific shares for the sinking fund)
Price stabilityImproved (regular repurchases provide price support)

Key point: A sinking fund is generally investor-friendly because it forces the issuer to commit funds to retire the preferred shares, reducing the risk that the issuer cannot meet its obligations.

Exam Tip: Gotchas

  • Sinking funds reduce credit risk for the investor but introduce some call risk on individual shares.
  • A sinking fund on preferred stock works the same way as on bonds; the exam may test this comparison.