Being included in a stockmarket index, particularly a benchmark index such as the Euro Stoxx 50 or the Stoxx Europe 50, is not just a matter of prestige. It is also a powerful lever for visibility and liquidity. When a company joins an index, it is automatically included in the portfolios of index funds (trackers, ETFs), which stimulates demand for its shares. Conversely, an exit can lead to mechanical sales and downward pressure on the stock.
These movements are therefore closely scrutinized. They reflect performance, market capitalization, liquidity, and sometimes sector arbitrage. Being "in the index" means staying on the radar of major international investors.
Euro Stoxx 50 vs. Stoxx Europe 50: what are the differences?
Let's take the latest changes announced by Stoxx in the Euro Stoxx 50 and Stoxx Europe 50 on September 1, 2025 as an example. First of all, what is the difference between these two indices? The Euro Stoxx 50 includes the 50 largest market capitalizations in the eurozone. It therefore excludes British, Swiss, and Scandinavian companies, and is often used as an economic barometer for countries sharing the single currency.
The Stoxx Europe 50, on the other hand, is geographically broader. It includes the 50 largest companies in Europe, across all regions. It therefore provides a more pan-European view of the market and combines companies whose reference currencies may differ (euro, Swiss franc, pound sterling, Danish krone, Swedish krona, etc.).
Selection for both indices is based on several technical criteria; the main one is free float; i.e., the portion of capital available for trading.
Prior to the arbitrage that will take effect on September 22, the Stoxx Europe 50 is dominated by:
- Sector-wise by financial stocks (21.6%), healthcare (18.5%) and industry (15.4%),
- Geographically by the UK (25.3%), France (22.8%) and Switzerland (18%),
The Euro Stoxx 50 is dominated by:
- Sector-wise by finance (25.3%), industry (20.15%) and information technology (14.6%),
- Geographically by France (36.1%), Germany (29.8%) and the Netherlands (12.7%).
The presence of large Swiss (Novartis and Roche), Danish (Novo Nordisk) and British (AstraZeneca) laboratories explains the strong representation of healthcare in the Stoxx Europe 50, which includes six non-eurozone stocks amongst its ten largest capitalizations (Nestlé and Shell in addition to the companies mentioned above).
What will change in September 2025
Three companies will be added to the Euro Stoxx 50:
- Deutsche Bank (Germany, banking),
- Siemens Energy (Germany, renewable energy),
- ArgenX (Belgium, biotechnology).
They replace:
- Nokia (Finland, telecommunications equipment),
- Stellantis (Italy, automotive),
- Pernod Ricard (France, spirits).
On the Stoxx Europe 50 side, there are two new entries:
- BBVA (Spain, banking),
- Rheinmetall (Germany, defense).
And two exits:
- BASF (chemicals),
- Mercedes-Benz (automotive).
These changes reflect several underlying trends in Europe.
First, banks have been back in favor for several quarters, which has been reflected in their capitalization. Deutsche Bank and BBVA have therefore become eligible for the two European blue chip indices.
Defense has been the big sector winner in recent years, driven by remilitarization: Rheinmetall is therefore benefiting from its meteoric rise.
Siemens Energy has been one of the pleasant surprises on the stock market over the past two years. After a difficult period, the German giant is now benefiting in particular from AI, which requires more and more energy installations.
Finally, ArgenX is the symbol of European biotech that has succeeded amid numerous failures. It is therefore highly regarded and is becoming increasingly influential.
On the downside, the automotive sector is in crisis and suffering from US customs policy, with Stellantis and Mercedes paying the price. After a surge in 2024, Nokia has lost ground again this year, with its market cap declining. So out goes the Finnish group, along with BASF and Pernod Ricard. Chemicals and spirits are two sectors that have come under pressure by tariff fears on global trade. Both companies have been overtaken in terms of market capitalization by other players.
We will find out in a few days whether the CAC 40 will undergo any changes in the fall: Euronext's scientific index committee will meet on September 11 to decide.
