VIX vs. Policy Uncertainty: What They Signal for Risk

Portfolio managers, analysts, and financial advisors face a tough call when sharp volatility and rising geopolitical uncertainty upend markets. They ask: Do I adjust course, reduce risk, or buy the dip?

While the instinct is often to reduce risk, traditional financial theory suggests that investors should be rewarded for embracing uncertainty and remaining patient. However, theory and practice don’t always align, especially in high-stakes decisions.

Market practitioners often turn to two widely used indicators to guide their choices: the Cboe Volatility Index (VIX) and the Economic Policy Uncertainty Index (EPU). However, understanding the type of uncertainty you're dealing with is critical, as misreading these signals can be costly.

The VIX and EPU are frequently treated as interchangeable stress signals. They shouldn't be. The VIX reflects market fear, while EPU tracks broader policy rifts. Confusing the two can lead to systematic mistakes, either being overly cautious when policy uncertainty is high, but markets are calm, or not reacting swiftly when genuine fear sets in. Misinterpreting these indicators can result in poor timing and missed opportunities, ultimately impacting returns.

The key question to ask is whether uncertainty stems from market fear or broader policy confusion, each carrying distinct implications for risk, timing, and portfolio positioning. Analysis of 35 years of data shows that the VIX and EPU capture different dimensions of unpredictability, with important consequences for portfolio risk.

To explore how these differences play out in practice, I examine how each indicator predicts forward equity returns across five distinct regimes.

The VIX reflects a measure of the implied volatility on S&P 500 options over the next 30 days. In plain terms it shows how much professional traders are paying to hedge against near-term market movements. When the VIX is high it means that the market is pricing in fear. This reflects traders committing real capital to hedge against risk.

The EPU Index, developed by Baker, Bloom, and Davis, combines newspaper references to policy uncertainty with measures of tax code ambiguity and disagreement among economic forecasters. Rather than capturing investor fear, it reflects the level of noise in the policy environment — how unclear the macroeconomic backdrop is. As a result, EPU is widely used in academic research and, while less prominent in day-to-day investing, is increasingly referenced by practitioners as a gauge of policy-driven uncertainty.

A high VIX tells you that investors are actively paying a premium to protect themselves. A high EPU tells you that commentators and forecasters are uncertain about policy directions.

Interestingly the EPU for the US has been consistently elevated since 2020, while the VIX has not been. These factors are related, but meaningfully distinct in their signaling.

I classified each month from 1990 to 2025 for the VIX and 1985 to 2025 for the EPU into five stress regimes based on where the current reading fell within one of the following trailing 5-year distributions: very low (0–20th percentile), low (20–40th), moderate (40–60th), high (60–80th), and very high (80–100th).

Using a rolling percentile approach ensures that each regime contains a roughly equal number of observations regardless of the absolute level of each index. Additionally, this means that each regime reflects the stress environment relative to recent history rather than an arbitrary absolute number.

I then calculated the price return of the S&P 500 over one-, three- and five-years from each month-end observation, along with the downside risk metrics such as the hit rate (percentage of periods with positive returns), the 10th percentile (a proxy for tail risk) and the median max drawdown experienced within each horizon.

The VIX exhibits a barbell pattern over a one-year horizon. Investors entering during periods of very low stress earn an average return of 11.9%, while those entering during periods of very high stress earn slightly more at 13.1% (see Figure 1). However, the path to those returns differs meaningfully. In low-stress environments, 89.8% of observations are positive, compared with just 78.2% during periods of very high stress.

Figure 1: 1-Year forward returns for VIX and EPU regimes

The EPU tells a different story. One-year returns are broadly similar across all policy uncertainty regimes, and the hit rate shows little variation as well (see Figures 1 and 2). Unlike the VIX, policy uncertainty does not meaningfully differentiate short-term return outcomes.

Figure 2: 1-Year hit rates for VIX and EPU in different regimes

Over longer horizons, these differences begin to converge. At the three-year horizon, returns across VIX regimes become more uniform, and the hit rate differences narrow. A similar pattern emerges for EPU: three years acts as an equalizer, with little distinction in returns across regimes.

At five years, the VIX distribution remains broadly uniform, with some evidence that moderate stress environments produce slightly stronger outcomes. The EPU, however, begins to show a different effect: higher levels of policy uncertainty are associated with stronger long-term returns.

Taken together, the results point to a clear divide. VIX-related uncertainty is primarily a short-term phenomenon, while policy uncertainty plays out over longer horizons, reflecting the slower-moving nature of macro and policy change.

The VIX reflects market-priced fear. When it rises, investors are paying for protection, and that corresponds to higher near-term risk — deeper drawdowns and lower hit rates. Although returns can be strong following elevated VIX, the path is more volatile and the advantage fades over time.

EPU, by contrast, captures policy noise. It shows little consistent relationship with downside risk, with drawdowns broadly similar across regimes and, at times, even larger following periods of low policy uncertainty. Its signal is more evident in long-term returns than in risk.

In practical terms, the VIX is a useful measure of market risk but a weak predictor of returns, while EPU provides some insight into long-term returns but offers limited guidance on risk.

Confusing the two can lead to systematic errors — becoming overly cautious when policy uncertainty is high, but markets are stable, and insufficiently cautious when markets are actively pricing in fear.

The VIX is best used as a risk management signal rather than a return indicator. Elevated levels point to a more volatile path for returns, supporting a more cautious stance — not because long-term returns are impaired, but because the near-term risk is higher.

EPU, by contrast, offers a weaker and more long-term signal. While periods of high policy uncertainty have at times been associated with stronger long-term outcomes, the relationship is inconsistent and not actionable over shorter horizons.

Time horizon is critical. VIX-driven effects tend to play out in the short term, while policy uncertainty unfolds more gradually. Investors entering during periods of elevated market stress may be rewarded, but only if they can tolerate volatility and remain invested.

Above all, not all uncertainty should be treated as equivalent. Market-priced fear signals near-term risk, while policy uncertainty reflects longer-term ambiguity that markets can often absorb.

Methodology note: Analysis uses monthly data from FRED (VIXCLS from January 1990, USEPUINDXD from January 1985) and S&P 500 price returns via Yahoo Finance. Stress regimes are defined using a rolling five-year percentile rank applied to each indicator at month-end. Forward returns are calculated as price returns (excluding dividends) over 1-, 3- and 5-year horizons. All analysis is conducted in Python and is available from the author on request.