How does inflation impact trading?

A growing body of research suggests that inflation doesn’t just erode purchasing power — it reshapes how financial markets function. This paper shows that when inflation rises, trading behavior changes in systematic ways: liquidity deteriorates, bid-ask spreads widen, and investors trade less on fundamentals and more on short-term noise. These effects amplify volatility and reduce informational efficiency. The result? Markets become less effective at aggregating information exactly when clarity is most needed.

Inflation and Trading

• Schnorpfeil, Weber, Hackethal
• Journal of Financial Economics, 2025
• A version of this paper can be found here
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Key Academic Insights

1. Inflation and Market Liquidity
The study finds a strong negative link between inflation and market liquidity. Periods of elevated inflation are associated with lower trading volumes, wider bid-ask spreads, and reduced depth across asset classes. This pattern holds even after controlling for volatility and macroeconomic uncertainty. The effect is strongest in equity and corporate bond markets, where inflation uncertainty discourages inventory holding by market makers.

2. Trading Behavior Shifts Under Inflation Pressure
Inflation shocks change the mix of investors’ trading motives. As real rates rise and uncertainty increases, short-term speculation grows relative to long-horizon investing. This leads to higher turnover without corresponding information flow — effectively, “noisy” trading that weakens price discovery.

3. Inflation Reduces Informational Efficiency
Using high-frequency data, the paper documents that return autocorrelation — a proxy for sluggish incorporation of information — rises in high-inflation periods. This suggests prices adjust more slowly to news, consistent with a decline in the market’s ability to process information efficiently.

4. Cross-Asset Spillovers Intensify
Inflation shocks trigger correlated adjustments across equities, bonds, and derivatives. This coordination is not driven by fundamentals but by liquidity demand and risk parity rebalancing. As a result, inflationary periods see stronger co-movements among assets, complicating diversification strategies.

Practical Applications for Investment Advisors

Rethink Liquidity in Portfolio Construction
Periods of high inflation are often accompanied by thinner markets and higher trading costs. Advisors should stress-test liquidity assumptions, especially for small caps, corporate bonds, and derivative exposures. Execution planning and position sizing become critical to preserve performance.

Inflation as a Signal for Regime-Sensitive Strategies
The findings suggest that inflation serves as a regime variable for trading efficiency. Momentum and mean-reversion strategies behave differently across inflation regimes — requiring adaptive thresholds or dynamic rebalancing.

Diversification May Fail When It’s Needed Most
As inflation links asset movements more tightly, traditional stock-bond diversification offers less protection. Advisors should consider alternative hedges such as inflation-linked bonds, commodities, or strategies explicitly designed for inflation volatility.

Human Behavior Matters More
The shift toward noise trading during inflationary stress highlights the need for behavioral discipline. Advisors should coach clients to focus on long-term fundamentals and avoid reactionary trading triggered by short-term inflation headlines.

How to Explain This to Clients

“When inflation rises, markets don’t just go down — they also get messy. Trading becomes more emotional, prices reflect less real information, and costs go up. It’s like trying to drive through fog: you can still move forward, but you need to slow down, plan your route carefully, and avoid sudden moves. That’s why during inflationary times, patience and good planning matter more than speed.”

The Most Important Chart from the Paper

Figure 3: Prior passthrough of return impact of inflation on expectations

The figure shows respondents’ 12-month return expectations of the German stock market
(vertical axis) relative to their perceived German-stock-return impact of inflationary periods in
Germany since 1950 (horizontal axis). We calculate the return impact of inflation by subtracting
respondents’ pre-treatment estimates of unconditional returns from inflationary-period return estimates.
Positive numbers hence imply a positive perceived nominal return impact of inflationary
periods. We partial out a standard set of controls we describe in Section 4 as well as unconditional
return estimates, following the covariate-adjustment approach by Cattaneo et al. (2024).

The results are hypothetical results and are NOT an indicator of future results and do NOT represent returns that any investor actually attained. Indexes are unmanaged and do not reflect management or trading fees, and one cannot invest directly in an index.

Abstract

We study how investors respond to inflation combining a customized survey experiment with trading data at a time of historically high inflation. Investors’ beliefs about the stock return–inflation relation are very heterogeneous in the cross section and on average too optimistic. Moreover, many investors appear unaware of inflation-hedging strategies despite being otherwise well-informed about prevailing inflation rates and asset returns. Consequently, whereas exogenous shifts in inflation expectations do not impact return expectations, information on past returns during periods of high inflation leads to negative updating about the perceived stock-return impact of inflation, which feeds into return expectations and subsequent actual trading behavior.