It’s usually claimed that small-cap shares are extra interest-rate sensitive than their large-cap counterparts due to their reliance on exterior financing. This appears believable. However what do the info say?
On this weblog put up, I discover the connection between small- and large-cap shares and interest-rate modifications utilizing the Shares, Bonds, Payments and Inflation® (SBBI®) month-to-month dataset — which is available to CFA Institute members — and the Robert Shiller long-bond rate dataset. I take advantage of graphs and correlations (and a bit of regression).
My important findings are:
- Small-stock month-to-month returns aren’t any extra delicate to fee modifications than large-stock returns.
- Small shares fare no worse on common than massive shares in periods of Federal Reserve (Fed) interest-rate tightenings, the place tightening durations are as outlined by Alan Blinder in a recent paper.
- The connection between shares and charges isn’t steady. There are durations when equities are extremely fee delicate, and durations after they aren’t.
- The Federal Reserve Financial institution of Chicago’s (Chicago Fed’s) Nationwide Monetary Situations Index (NFCI) — a proxy for ease of general entry to capital — has about the identical relationship with small-stock returns as with massive.
R Code for calculations carried out and charts rendered may be discovered within the on-line supplement to this put up.
Shares and Charges: The Huge Image
I begin with the total interval for the SBBI® dataset: January 1926 to April 2024. The left panel in Chart 1 reveals the correlation between small-stock month-to-month returns and the long-government bond rate of interest (hereafter, the “lengthy fee” or simply “fee”) from the inception of the SBBI® dataset in 1926 to April 2024, which is the final obtainable month of SBBI® returns. The correct panel in Chart 1 reveals the correlation between large-stock month-to-month returns and the lengthy fee throughout the identical interval.
The correlation between massive shares and fee modifications is modestly damaging (-0.1) and important on the 95% stage. The correlation between small shares and fee modifications shouldn’t be important. These outcomes are sturdy to lagging the speed change variable by one interval and to proscribing fee modifications to optimistic values. That’s, accounting for potential delayed results and limiting fee modifications to the possibly hostile doesn’t change the outcomes.
Chart 1. Month-to-month small- (left) and large-stock (proper) returns versus long-rate modifications, 1926 to April 2024.

These correlations are suggestive, however clearly not conclusive. The lengthy timeframe — practically a century — may masks necessary shorter-term relationships.
Desk 1 subsequently reveals the identical statistic however grouped, considerably arbitrarily, by decade.
Desk 1. Giant- and small-cap inventory month-to-month return correlations with all lengthy fee modifications.

When seen this fashion, the info recommend that there could possibly be meaningfully lengthy durations when correlations differ from zero. I omit confidence intervals right here, however they don’t embody zero when correlations are comparatively massive in an absolute sense. Correlations are normally of the anticipated signal (damaging).

There doesn’t appear to be a lot distinction in the best way that small and enormous shares reply to long-rate modifications, with the potential exception of the previous few years (the 2020s). These findings are sturdy to lagging the rate-change variable by one interval. Limiting fee modifications to optimistic observations modifications each the signal of correlations and (considerably) their magnitude in some durations, as proven in Desk 2. Nothing about Desk 2’s outcomes, nevertheless, suggests a distinction within the response of small and enormous shares to an increase in charges.
Desk 2. Giant- and small-cap inventory month-to-month return correlations with optimistic long-rate modifications.

However, as famous, a long time are arbitrary durations. Chart 2 subsequently reveals the rolling 60-month correlation between the small-, large-, and long-rate change sequence for the size of the SBBI® dataset.
Chart 2. Rolling 60-month correlations between small (left) and enormous (proper) shares and long-rate modifications.

Two options are noteworthy. One, the charts are practically indistinguishable visually, vertical-axis values apart. Small and enormous shares seem to exhibit comparable conduct in response to fee modifications. It’s onerous to keep away from the inference that small-cap shares don’t reply otherwise to long-rate modifications than large-cap shares. And two, the stock-rate relationship varies, and may have the “mistaken” signal for lengthy durations.
Eradicating Market Results
Might the noticed comparable response of enormous and small shares to long-rate modifications be as a result of affect of “the market” (large-stock returns) on small shares? It appears believable that broad market results may masks an hostile response of small shares to rising borrowing prices. Eradicating them may give us a greater sense of the impact of long-rate modifications on small-stock returns.
I do that by first regressing small-stock month-to-month returns on large-stock month-to-month returns (a proxy for “the market”). I then calculate partial correlation utilizing the residuals from this regression, which mirror the non-market a part of small-stock returns and long-rate modifications.[1]
Total (1926 – April 2024), the partial correlation is once more not totally different from zero. Nonetheless, as proven in Chart 3, the rolling, 60-month partial correlation has been principally (although not all the time) optimistic — the alternative of the anticipated signal — and typically massive, significantly recently. Controlling for “market beta” subsequently does appear to affect the connection between small shares and lengthy charges. These outcomes in all probability aren’t virtually significant or helpful, nevertheless.
Chart 3. Rolling 60-month partial correlations between small shares and fee modifications.

Financial Coverage and Returns
Small-cap shares could possibly be extra delicate to shorter-term charges to which their borrowing prices are extra carefully linked.
Desk 3 subsequently reveals the common annualized efficiency (in decimals, so, e.g., 0.03 = 3%) of small and enormous shares throughout the 12 Fed tightening episodes recognized by Alan Blinder (listed in column 1) in his paper on “soft landings.”
Desk 3. Giant- and small-stock efficiency throughout Blinder’s financial tightenings.

Earlier than the early Eighties, a researcher might need concluded that small shares carried out higher than massive shares when the Fed was climbing. The fourth column (“diff”), which reveals the distinction between small and enormous inventory returns, was optimistic in all tightenings as much as that point.
Since then, small shares have underperformed throughout tightenings extra usually than they’ve outperformed. However the distinction appears modest.
Monetary Situations
Maybe Fed-induced short-term fee will increase and long-rate rises don’t adequately proxy for availability of credit score.
Helpfully, the Chicago Fed maintains the NFCI, which summarizes monetary situations utilizing a weighted common of greater than 100 indicators of threat, credit score, and leverage. The smaller (extra damaging) the NFCI’s worth, the looser (extra accommodative) are monetary situations.
The standard knowledge that small shares are deprived relative to massive shares in less-hospitable monetary situations suggests a damaging correlation between the NFCI and small-stock returns. And deteriorating monetary situations, as mirrored by optimistic NFCI values, ought to be extra negatively associated to small-cap returns than to large-cap returns.
To check this, I first take away potential NFCI time developments by differencing (subtracting from every worth the earlier worth) the sequence, which shouldn’t change the anticipated correlation signal (damaging). Then, I repeat the calculations above. I discover no distinction within the response of small and enormous shares to modifications in monetary situations as proven within the on-line supplement to this weblog. In neither case does the change within the NFCI or its lagged worth seem associated to returns.
Keep away from Broad Statements About Small Shares and Charges
Utilizing CFAI SBBI® and Robert Shiller information on long-government bond charges, I don’t discover proof to help the declare that small and enormous shares reply to fee modifications otherwise. Moreover, small and enormous shares don’t react otherwise to the short-term fee rises that happen throughout Fed tightenings or to the modifications in capital-market exercise as measured by a broad monetary situations index.
As Desk 1 reveals, inventory returns and fee modifications have been virtually all the time inversely associated till the last decade following the Nice Recession, and to roughly the identical diploma. Desk 3 factors to the identical conclusion for episodes of Fed tightening.
The previous result’s per principle. The latter is opposite to the standard knowledge that small shares (as proxied by the SBBI® small-cap index) are uniquely susceptible to rising charges.
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The writer is a Registered Funding Advisor consultant of Armstrong Advisory Group. The data contained herein represents Fandetti’s impartial view or analysis and doesn’t symbolize solicitation, promoting, or analysis from Armstrong Advisory Group. It has been obtained from or is predicated upon sources believed to be dependable, however its accuracy and completeness usually are not assured. This isn’t meant to be a proposal to purchase, promote, or maintain any securities.
[1] This might in fact even be estimated utilizing the a number of regression of small-stock returns on rates of interest, controlling for large-stock returns.