For nearly every practical purpose, the equity risk premium is the same as the market risk premium, even though the two terms describe slightly different things in theory. The equity risk premium measures the extra return investors expect from stocks over risk-free government bonds. The market risk premium, in the Capital Asset Pricing Model, is broader: it covers every risky asset in existence, from private companies to real estate to commodities. Because no one can price all of those assets in real time, analysts fill in the “market” premium with stock market data, and the two numbers effectively merge.
What Each Term Technically Means
The equity risk premium is the gap between stock returns and the risk-free rate. If stocks have returned roughly 10% per year in nominal terms over long stretches and Treasury bonds have yielded around 4%, the equity risk premium is that spread. It compensates investors for the fact that stock prices swing unpredictably, companies go bankrupt, and downturns produce real losses. Over 1996 through mid-2022, the S&P 500 delivered a mean annual total return of about 9% nominal and roughly 6.8% after inflation, consistent with longer historical patterns going back two centuries.1McKinsey & Company. Markets Will Be Markets: An Analysis of Long-Term Returns From the S&P 500 Subtract a risk-free rate, and historical equity risk premium estimates typically land between 4% and 7%.
The market risk premium comes from a different starting point. CAPM imagines a perfectly diversified investor holding a slice of every investable asset on the planet: public stocks, corporate bonds, real estate, commodities, private businesses. The market risk premium is the expected return of that entire portfolio minus the risk-free rate. It represents compensation for systematic risk, the economy-wide shocks that no amount of diversification can remove.
Why the Distinction Rarely Matters in Practice
The technical relationship is simple: the equity risk premium is a subset of the market risk premium. Stocks are one category of risky asset; the market portfolio contains all of them. In a textbook these would be different numbers, because private real estate and commodities do not move in lockstep with the S&P 500.
The problem is that no one can actually calculate a true market risk premium. That would require real-time valuations of every private business, every parcel of real estate, and every barrel of oil in storage. Stock exchanges, by contrast, produce transparent second-by-second prices. So when an analyst plugs a market risk premium into a valuation model, the input almost always comes from stock market data. The substitution is universal enough that hearing the two terms used interchangeably in earnings calls or investment committee meetings is standard.
How Both Show Up in CAPM
The Capital Asset Pricing Model ties the concepts together in one equation:
Expected Return = Risk-Free Rate + Beta × (Expected Market Return − Risk-Free Rate).
The bracketed term is the market risk premium, which in practice gets filled with an equity risk premium estimate. Beta measures how sensitive a specific stock is to overall market swings. A beta of 1.0 moves in line with the market; a beta of 1.5 tends to swing 50% more in either direction. Higher-beta stocks command a larger premium because investors bearing more volatility expect more compensation.
What Actually Moves the Number
If the definitional gap between “equity” and “market” premium rarely changes an answer, the choices underneath the premium calculation change it a great deal. These are the decisions worth paying attention to.
Which Risk-Free Rate You Use
Every premium calculation starts with the risk-free rate, which in the United States means a Treasury yield. Short-term Treasury bills yielded roughly 3.6% to 3.7% in early 2026.2U.S. Department of the Treasury. Daily Treasury Bill Rates The 10-year Treasury sat at about 4.06% in early March 2026.3St. Louis Fed FRED. Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity Using a 10-year bond produces a smaller equity risk premium than using a 3-month bill, because the bond already carries duration risk of its own. Most practitioners match the maturity to the valuation horizon: bills for short-term work, 10-year bonds for cash flows discounted years into the future.4NYU Stern – Aswath Damodaran. Estimating Equity Risk Premiums
Historical Average or Implied Estimate
There are two fundamentally different ways to estimate the premium, and they often disagree.
The historical approach looks backward. Take decades of stock returns, subtract the risk-free rate over the same period, average the difference. Using U.S. data from 1926 through 2005, this method produces an equity risk premium of roughly 4.9% to 6.5% over government bonds depending on whether you use a geometric or arithmetic average. The geometric average compounds year over year and better reflects what a long-term investor actually earned; the arithmetic version runs higher. For long-horizon work, the geometric figure is generally the more appropriate choice.5NYU Stern. Chapter 4 Derivations – Discussion Issues and Derivations
The implied approach looks forward. Take the current level of a broad index like the S&P 500, estimate future dividends and earnings growth, and solve for the discount rate that makes those cash flows equal to today’s price. Subtract the risk-free rate and you have the implied premium. As of March 2026, Aswath Damodaran’s widely referenced estimate placed the implied premium at approximately 4.38%.6NYU Stern. Home Page for Aswath Damodaran It updates with every market move, making it more responsive to current conditions than a backward-looking average that still contains data from the Great Depression.
Survivorship Bias in U.S. Data
U.S. historical returns come with a catch. The United States had the most successful stock market of the 20th century, but that outcome was not guaranteed in 1900. An investor then could just as easily have concentrated in Russia, Argentina, or China, all of which experienced catastrophic losses from wars, revolutions, or hyperinflation. Measuring only the winner after the fact inflates the apparent reward for holding stocks.
Recent research suggests survivorship bias may account for roughly one-third of the measured U.S. equity risk premium over the past century, overstating the historical figure by about 2 percentage points. A commonly cited 6% historical premium moves closer to 4% once you adjust for the fact that the U.S. turned out to be an unusually lucky survivor.
Country Risk Adjustments Outside the U.S.
When applying a premium to companies outside the United States, analysts add a country risk premium reflecting the added uncertainty of investing in less stable economies. The adjustment starts with a country’s sovereign default spread and scales it by the relative volatility of that country’s stock market.
Sizes vary widely. As of early 2026, Germany carried no country risk premium above the mature-market baseline, Brazil’s premium was approximately 3.24%, and Turkey’s was about 4.66%.7NYU Stern. Country Default Spreads and Risk Premiums Valuing a Brazilian company means adding that 3.24% on top of a base equity risk premium, which substantially raises the discount rate and lowers the estimated value. Skipping this step is one of the more common valuation mistakes in international analysis.
Nominal Versus Real
The risk-free rate and expected market return must be expressed the same way, both nominal or both real, or the resulting premium is meaningless. Cash flows projected in today’s dollars without inflation growth call for a real discount rate. Cash flows that grow with inflation, as most corporate projections do, call for nominal figures throughout.4NYU Stern – Aswath Damodaran. Estimating Equity Risk Premiums Mixing the two can throw a valuation off by 20% or more.
The Bottom Line
Treating the equity risk premium and the market risk premium as the same figure will not lead you astray for practical investment work. The theoretical distinction lives in academic papers and vanishes the moment anyone opens a spreadsheet. What actually shapes your answer is the set of choices underneath the number: which Treasury maturity you use, whether you rely on historical or implied estimates, whether you correct for survivorship bias, whether you add a country premium, and whether you keep nominal and real figures consistent. Each of those decisions can swing a valuation by several percentage points, far more than the definitional gap between “equity” and “market” ever will.