{"id":8,"date":"2026-07-18T09:47:32","date_gmt":"2026-07-18T09:47:32","guid":{"rendered":"https:\/\/chat-demo-dev.quaestra.ai\/?page_id=8"},"modified":"2026-07-18T09:47:32","modified_gmt":"2026-07-18T09:47:32","slug":"a-ricardo-research-perspective","status":"publish","type":"page","link":"https:\/\/chat-demo-dev.quaestra.ai\/","title":{"rendered":"A Ricardo Research Perspective\u00a0"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Passive investing has become one of the defining forces in global capital markets. In this paper, co-authored by our director&nbsp;<strong>Professor Dimitri&nbsp;Vayanos<\/strong>, together with&nbsp;<strong>Hao Jiang<\/strong>&nbsp;and&nbsp;<strong>Lu Zheng<\/strong>, the authors uncover a powerful and structural mechanism through which passive flows reshape asset prices. Their central finding is clear: as passive investing grows, it disproportionately boosts the valuations and volatilities of the largest firms in the market, even when indices include all listed companies.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This dynamic contributes directly to the rise of so-called mega firms, the increasing concentration of equity indices, and the widening gap between the largest firms and the rest of the market.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Core Insight: Why Passive Flows Favour the Largest Firms&nbsp;<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The authors show that passive investing changes how&nbsp;markets price risk. Rather than affecting all firms uniformly, passive flows have size-dependent consequences driven by differences in how systematic and idiosyncratic risks are discounted.&nbsp;<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Repricing systematic and idiosyncratic risk<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Smaller and mid-sized firms experience idiosyncratic shocks that have little\u00a0bearing on\u00a0movements in the broader market, so their cashflows remain discounted close to the risk-free rate.\u00a0<\/li>\n\n\n\n<li>The largest firms generate idiosyncratic shocks that carry macroeconomic weight, meaning their individual disturbances\u00a0shift\u00a0the wider market. As passive flows increase, the compensation\u00a0required\u00a0for bearing this risk falls, lifting the valuations of large firms more than those of smaller companies.\u00a0<\/li>\n<\/ul>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>Rising volatility that disproportionately affects large firms<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Passive flows raise both price levels and price volatility.\u00a0<\/li>\n\n\n\n<li>For large firms,\u00a0additional\u00a0volatility is concentrated in a single stock rather than diversified across a portfolio.\u00a0<\/li>\n\n\n\n<li>This means the usual risk-offsetting mechanisms are weaker, so the increase in volatility does\u00a0less\u00a0to temper the rise in valuations.\u00a0<\/li>\n<\/ul>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>Noise traders amplify the effect<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>When noise traders hold disproportionate positions in certain large firms, passive inflows reinforce existing imbalances.\u00a0<\/li>\n\n\n\n<li>This interaction creates further upward pressure on the prices of the biggest companies, especially when experts hold short positions or idiosyncratic supply is limited.\u00a0<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">What the Model Predicts&nbsp;<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The model generates several predictions that match observed patterns in equity markets.&nbsp;<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Large firms rise more than the overall market<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The authors estimate that passive investing caused the largest 50 US firms to rise around 30 per cent more than the market between 1996 and 2020.&nbsp;<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>Volatility increases primarily for the biggest firms<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Passive flows increase both total and idiosyncratic volatility for large firms, while having little noticeable effect on smaller firms.&nbsp;<\/p>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>Even reallocations from active to passive push markets up<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The market continues to rise even when passive flows reflect a switch from active to passive funds rather than new capital entering the market. The effect is driven by the uplift in the valuations of the largest firms, which outweighs any negative impact on smaller or undervalued firms.&nbsp;<\/p>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li>Index additions produce size-dependent price effects<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">When a company is added to an index such as the S&amp;P 500, its share price increases. The effect is modest for small firms but significant for larger firms, particularly those already heavily held by noise traders.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Empirical Evidence: What the Data Show&nbsp;<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Using S&amp;P 500 index fund flows and firm-level data for 1996\u20132020, the authors provide robust empirical support for their theory.&nbsp;<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Large firms outperform during high passive-flow quarters<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">In quarters&nbsp;characterised&nbsp;by meaningful inflows into S&amp;P 500 index funds, stocks of the largest firms reliably outperform the index.&nbsp;<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>Index concentration increases with passive flows<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Measures such as the combined weight of the top ten firms, dispersion of index weights, and the Herfindahl index all rise with passive inflows, making the index increasingly top-heavy.&nbsp;<\/p>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>Volatility rises for large firms<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Passive flows materially increase both total and idiosyncratic volatility for the largest firms, with far weaker effects for others.&nbsp;<\/p>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li>Index additions show size and demand dependence<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Large firms added to the index&nbsp;experience&nbsp;the biggest valuation jumps, and firms in high noise-trader demand benefit even more.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Broader Implications&nbsp;<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Financing costs fall most for mega firms<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Passive flows disproportionately lower discount rates for the largest firms, giving them structurally cheaper access to capital.&nbsp;<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>Contributing to rising industry concentration<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">By boosting the relative position of large firms, passive investing may be accelerating the rise of so-called superstar firms and increasing the skew in the firm-size distribution.&nbsp;<\/p>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>Potential misallocation of capital<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">If capital is disproportionately drawn towards already-large firms, it may&nbsp;fail to&nbsp;reach the most productive investment opportunities, contributing to weaker long-term productivity growth.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">A Contribution from Our Own Team&nbsp;<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This paper draws directly on the work of our director&nbsp;<strong>Professor Dimitri&nbsp;Vayanos<\/strong>, whose leadership in understanding institutional investment dynamics continues to shape the way we help long-horizon investors interpret market structure. His involvement ensures that the insights from this research are integrated into our broader approach to&nbsp;analysing&nbsp;distortions in modern capital markets.&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Passive investing has become one of the defining forces in global capital markets. In this paper, co-authored by our director&nbsp;Professor Dimitri&nbsp;Vayanos, together with&nbsp;Hao Jiang&nbsp;and&nbsp;Lu Zheng, the authors uncover a powerful and structural mechanism through which passive flows reshape asset prices. Their central finding is clear: as passive investing grows, it disproportionately boosts the valuations and &hellip; <a href=\"https:\/\/chat-demo-dev.quaestra.ai\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">A Ricardo Research Perspective\u00a0<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-8","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/pages\/8","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8"}],"version-history":[{"count":1,"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/pages\/8\/revisions"}],"predecessor-version":[{"id":9,"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=\/wp\/v2\/pages\/8\/revisions\/9"}],"wp:attachment":[{"href":"https:\/\/chat-demo-dev.quaestra.ai\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}