Introduction
The CAC 40 is France's benchmark equity index, comprising the 40 largest companies by free-float market capitalisation listed on Euronext Paris. It serves as the primary barometer of French corporate health and is one of Europe's most closely watched indices alongside Germany's DAX and the UK's FTSE 100.
What the CAC 40 Contains
The index is maintained by Euronext and reviewed quarterly by an independent Scientific Advisory Committee, which meets in March, June, September, and December. Eligibility requires a company to be listed on Euronext Paris and rank among the top 100 French-listed securities by free-float market cap and average daily traded volume over the preceding 12 months. Crucially, nationality is not a strict criterion — a company incorporated outside France can qualify if its primary listing is in Paris, which is why STMicroelectronics (STMPA.PA), incorporated in the Netherlands and headquartered in Geneva, sits in the index.
As of mid-2025, the index is heavily weighted toward luxury goods, energy, and financial services. LVMH (MC.PA) alone has historically commanded a weighting above 10%, making it the single largest constituent and giving the index unusual sensitivity to Chinese consumer demand. Other major names include TotalEnergies (TTE.PA), Hermès (RMS.PA), Schneider Electric (SU.PA), AXA (CS.PA), and BNP Paribas (BNP.PA). The top five constituents collectively represent roughly 35–40% of the index, meaning the CAC 40 is considerably concentrated relative to its breadth.
Weights are capped at 15% per constituent at each quarterly rebalancing, a rule introduced to prevent any single stock from distorting index-level returns during periods of extreme price appreciation.
European Context
Under MiFID II, financial products tracking the CAC 40 — including ETFs, futures, and structured products — are subject to strict transparency obligations. Providers must publish pre- and post-trade data through Approved Publication Arrangements (APAs), and retail investors gain access to standardised cost disclosures under the Key Information Document (KID) framework mandated by ESMA's PRIIPs regulation. The CAC 40 futures contract traded on Euronext Derivatives Paris (ticker: FCE) is one of the most liquid equity index futures in the eurozone, with daily notional turnover routinely exceeding €5 billion.
France's sectoral profile also distinguishes the CAC 40 from European peers. Unlike the DAX, which is industrial and chemical-heavy, or the FTSE 100, which carries substantial oil and mining exposure, the CAC 40's luxury weighting means it correlates strongly with global discretionary spending cycles rather than purely European economic conditions. This makes it a frequent vehicle for investors seeking proxy exposure to Chinese consumption without directly holding Hong Kong or mainland Chinese equities.
Historical Episodes
In March 2020, the CAC 40 collapsed from approximately 6,100 points to a low near 3,754 — a drawdown of roughly 38% in five weeks — as Covid-19 lockdowns froze European economies. The speed of the decline triggered repeated use of Euronext's volatility interruption mechanism, which temporarily halts trading when a constituent price moves beyond predefined thresholds, a safeguard reinforced by ESMA guidelines on circuit breakers.
In 2022, the index shed around 9.5% across the full year despite a strong recovery from post-pandemic highs, largely driven by the energy shock following Russia's invasion of Ukraine and aggressive ECB rate tightening that compressed valuations in financial and real estate names.
Conversely, 2023 saw the CAC 40 cross the 7,500 level for the first time and briefly approach 7,600, powered by resilient earnings from luxury conglomerates. LVMH's market capitalisation at its 2023 peak briefly exceeded €400 billion, making it the first European company to surpass that threshold.
What to Watch
The quarterly rebalancing calendar — March, June, September, December — determines when new entrants replace underperforming constituents, and announcements typically move the affected stocks by 1–3% in the days surrounding confirmation.
Chinese consumer confidence data materially influences the CAC 40 given LVMH and Hermès combined represent a double-digit percentage of the index.
ECB monetary policy decisions directly affect BNP Paribas, Crédit Agricole (ACA.PA), and AXA, which together give the index meaningful sensitivity to eurozone interest rate direction.
TotalEnergies' weighting means Brent crude price swings of more than 5% in a week will visibly influence index-level performance even when the broader market is stable.
Political risk in France — budget votes, confidence motions, and presidential election cycles — has historically triggered elevated implied volatility in CAC 40 options, particularly in contracts tied to Euronext's VCAC volatility index.
ETF flows into major CAC 40 trackers such as Amundi's CAC 40 UCITS ETF (C40.PA) serve as a real-time signal of institutional positioning, with large inflows often preceding short-term momentum in the index.
Constituent changes themselves are worth monitoring: when a company is added to the CAC 40, passive funds tracking the index are mechanically required to purchase shares, creating predictable demand that active traders routinely front-run.