Inflation Risk (Purchasing Power Risk)

Credit risk threatens whether you get paid. Inflation risk threatens whether those payments are worth anything when you receive them.


What Is Inflation Risk?

  • Inflation risk (also called purchasing power risk) is the risk that rising prices reduce the real return on an investment
  • Real return = nominal return minus inflation
  • If your bond pays 3% but inflation is 4%, your purchasing power is actually declining
  • This risk operates silently: you still receive your payments, but each dollar buys less

Think of it this way: Your bond still pays the same $50 every year. But if a gallon of milk went from $4 to $6, that $50 covers fewer groceries than it used to. Your dollars are the same; their buying power is not.

Which Investments Are Most Vulnerable?

SecurityInflation Risk LevelWhy
Cash / savings accountsHighestReturns rarely keep pace with inflation
Long-term fixed-rate bondsHighFixed payments locked in for decades
Short-term bonds / T-BillsModerateShorter terms allow faster rate adjustment
TIPSVery lowPrincipal adjusts with Consumer Price Index (CPI)
EquitiesLowerCompany earnings can grow with rising prices
Real estate / REITsLowerProperty values and rents tend to rise with inflation

Key Relationships

  • Fixed-income investments are most vulnerable because their payments are fixed in nominal terms
  • A bond paying $50 per year buys the same goods whether inflation is 1% or 10%. At 10% inflation, that $50 is worth significantly less in real terms
  • Equities offer better inflation protection because companies can raise prices, increasing revenues and earnings
  • TIPS (Treasury Inflation-Protected Securities) directly address inflation risk. The principal adjusts semiannually based on changes in the CPI
  • Real assets (real estate, commodities) may also serve as inflation hedges

Exam Tip: Gotchas

  • Fixed-income securities (especially long-term bonds) are the most vulnerable to inflation risk. Equities offer better inflation protection because company earnings can grow with rising prices.
  • The exam frequently tests which asset class is most/least affected by inflation. Cash and long-term bonds are most exposed; equities and real assets are least exposed.

Inflation drives central bank policy, which in turn drives interest rates. Next, we'll see how changing interest rates create their own form of risk for bond investors.