Direct Answer

Factor premiums are systematic return differences that have persisted over long periods. The equity risk premium (stocks over T-bills) averages about 5-6% annually over 90+ years. Value, size, and momentum premiums each average 2-5% annually, though all are cyclical and can underperform for a decade or more.

Factor Investing Premiums Reference

By Swoopr Editorial Team · Published · AI-assisted research, editorially reviewed.

Historical Factor Premiums (U.S., ~1963-2024)

FactorLong-Short Premium (ann.)Sharpe RatioKey MetricWorst Decade
Market (ERP)+5.5% over T-bills0.42Beta vs. market2000s (-1.0%/yr)
Value (HML)+3.7%0.31Book/Price ratio2010s (-3.1%/yr)
Size (SMB)+2.9%0.24Market cap1980s (+1.1%/yr)
Momentum (UMD)+7.8%0.5012m-1m return2009 crash (-84%)
Profitability (RMW)+3.6%0.49Operating profit2000s (modest)
Investment (CMA)+3.0%0.45Asset growthVaries
Low Volatility+1.8% (risk-adj)0.35Beta/Idio. vol.2017-2019
Quality+3.5%0.48ROE/AccrualsLimited data

Source: Fama-French Data Library, AQR Capital Management research. Data through 2019; last checked September 2026.

Frequently Asked Questions

What is factor investing?

Factor investing (also called smart beta or systematic investing) targets specific, documented return premiums beyond market exposure. Factors are characteristics that have historically predicted higher returns, such as low valuation (value), small market cap (size), or recent price momentum.

Are factor premiums reliable?

Factor premiums are real but cyclical and uncertain. All major factors have experienced decade-long periods of underperformance. Value underperformed for the entire 2010s. Investors must have conviction in the factor's theoretical basis and long time horizons to capture premiums without abandoning the strategy during drawdowns.

How do I implement factor investing?

Most retail investors access factors through factor ETFs (Dimensional Fund Advisors, AQR, iShares, Vanguard) or through direct indexing services. Tilting toward multiple uncorrelated factors (e.g., value + momentum) provides more consistent premium capture than any single factor, since factor premiums are largely uncorrelated.

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If you reference this table in your own work, use the following citation format and add the date you accessed it:

Swoopr Editorial Team. (2026). Factor Investing Premiums Reference. Swoopr Investment. https://www.getswoopr.com/tables/portfolio/factor-investing-premiums-reference/

Check the figures against the primary sources listed under References before you rely on or republish them; the series they come from are revised.

References