The Money Market: Europe's Invisible Thermometer and Why the €STR Is Its New Beating Heart
Imagine a vast, invisible marketplace where hundreds of billions of euros change hands every day in just a few hours. This is where banks lend money to one another to balance their books before closing. This is the money market: the daily pulse of European finance.
What exactly is the money market?
It's where banks, corporations, and investment funds refinance themselves on a very short-term basis (often overnight — literally for one night). When a bank has excess liquidity in the evening, it lends to another that falls short. The rate at which these loans are made is the price of short-term money — a thermometer of liquidity and confidence in the economy.
Until 2019, this role was held by EONIA (Euro Overnight Index Average), a rate calculated from bank declarations. But after the Libor scandal (rate manipulation), the ECB decided to overhaul the system entirely. Since January 2, 2019, the €STR (Euro Short-Term Rate) has become the new official benchmark rate.
The €STR: Europe's new money thermometer
The €STR measures the average rate at which banks lend to each other without collateral, for a 24-hour period. In short, it's the real price of money "day to day."
How is it calculated? (and why it's tamper-proof)
Unlike EONIA (based on declarations), the €STR is calculated solely from actual transactions collected from around fifty of the largest banks in the eurozone. The methodology is rigorous:
- The ECB collects all unsecured transactions from the previous day.
- It sorts the rates and removes the lowest 25% and the highest 25% (a technique known as the trimmed mean).
- It calculates the weighted average of the remaining 50%.
- Publication: every business day at 8:00 AM CET (Monday's rate is published Tuesday morning).
This formula makes the €STR virtually impossible to manipulate: it reflects what actually happened, not what banks "say" they would do.
Why the €STR matters to you (even if you're not a banker)
The €STR directly influences your financial daily life:
- Your savings: money market funds, term deposits, and indexed savings accounts (Livret A, LDDS in France) are based on it. When the €STR rises, your bank earns more on its interbank placements → it can raise your rates (though often with a delay).
- Your loans: variable-rate loans (mortgages, consumer credit) are often indexed to the €STR + a margin. A rising €STR = higher monthly payments.
- Businesses: corporate treasuries invest their surpluses in the money market. A low €STR = cheap financing; a high €STR = more expensive funding costs.
Next-generation money market funds, like those offered by Louis.finance, aim to beat the €STR yield through continuous market access and disintermediation from traditional financial institutions.
€STR vs EURIBOR: They don't play in the same league
| Criteria | €STR (Euro Short-Term Rate) | EURIBOR (Euro Interbank Offered Rate) |
|---|---|---|
| Loan duration | 24 hours (overnight) | 1 week to 12 months |
| Data source | Actual transactions recorded by the ECB | Bank declarations about their intentions |
| Collateral | Unsecured | Unsecured |
| Primary use | Money market funds, treasury, 24/7 yield | Mortgages, corporate loans |
| Responsiveness | Reacts immediately to ECB decisions | Anticipates medium-term rate changes |
The €STR is the "actual" rate of the day; EURIBOR is the "anticipated" rate for the months ahead. Both have coexisted since 2019.
The impact on the Livret A and your investments
The Livret A is — alongside current accounts and euro-denominated life insurance funds — one of the French public's favourite savings products, and its yield derives directly from the €STR. The Livret A rate (currently frozen at 1.50% at the time of writing) is recalculated every 6 months using the formula:
Livret A rate = max (Inflation + 0.5%; average €STR + margin)
When the €STR rises sustainably, it "pushes" the Livret A rate upward. But the formula is capped and adjusted by the government, which sometimes creates a lag — as we saw throughout 2023 & 2024 (cf. BFM TV & Meilleurtaux).
Next-generation money markets (which Louis.finance connects to for its investment solutions) capture the €STR yield directly, plus a significant outperformance. This premium comes from several structural advantages:
- 24/7 access: instant and continuous, free from the time constraints of traditional banking systems
- Real-time liquidity: via decentralised money market protocols (over-collateralised lending/borrowing on euro stablecoins)
- No intermediaries: no administrative middlemen or settlement delays (no waiting for committee decisions, T+1 or T+2 settlements, etc.)
The yield obtained is therefore variable and depends directly on the supply/demand balance for liquidity on these protocols: the stronger the borrowing demand (in € stablecoins), the more rates climb above the €STR.
In practice, solutions like Louis.finance (developed by Cometh, MiCA-regulated in France) allow businesses to access yields historically superior to the compounded €STR, while maintaining immediate fund availability and using euro-pegged stablecoins. This is a major evolution: moving from traditional money market funds (often €STR + 10–40 bps after fees and constraints) to next-generation money markets that, by capturing the true scarcity of liquidity, generate a much higher risk/scarcity premium — without sacrificing liquidity.
The €STR in the 2025-2026 context
In 2025, the average €STR fluctuated around 2.70–3.50% (depending on ECB policy). In February 2026, it remains elevated compared to the 2010–2020 period (when it was negative or close to zero).
This reflects:
- Persistent inflation
- A cautious ECB regarding rate cuts
For savers, this is an opportunity: money market yields have become attractive again. For borrowers, it's a signal for caution.
Conclusion: The €STR, the new beating heart of European finance
The €STR is not just a number published every morning by the ECB: it is the daily reflection of confidence, liquidity, and the real cost of money in the eurozone. It influences your savings accounts, your loans, corporate treasuries, and even innovative money market products like those from Louis.finance.
In a world where money never sleeps, understanding the €STR means understanding the pulse of the European economy. And that is exactly what next-generation money markets harness: direct, continuous, and high-performing access to that pulse, within a secure and regulated framework.
If you'd like to learn more about how Louis.finance uses the €STR as a benchmark to generate 24/7 yield, discover our solutions.