1&1 stock benefits from strong SDAX weighting while investors look to latest annual figures

Published on 09/16/2026 at 20:21 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

1&1 stock currently represents the largest market capitalization in the SDAX, with a valuation in the low billions of euros as of September 16, 2026. The company’s most recent available full-year figures stem from the 2025 annual report and serve as a historical benchmark for investors.

Bauhaus-Grafikposter mit TELEKOMMUNIKATION-Schrift und geometrischen Signalwellen — Bauhaus-Poster mit TELEKOMMUNIKATION und geometrischen Wellen repräsentiert Branche der 1&1 AG DE0005545503, Illustration mit AI erstellt.

1&1 stock (ISIN DE0005545503) stands out in the SDAX as one of its heaviest constituents, with the shares currently underpinning a multibillion-euro market capitalization as of September 16, 2026. For investors, this size factor is central when assessing the risk-return profile of the telecommunications and internet-services group.

SDAX context and current market positioning

According to finanzen.ch on September 16, 2026, the SDAX reached an intraday level of 18,173.37 points, with its constituents collectively valued at EUR 91.894 billion. In this overview, 1&1 stock is highlighted with an indicative market capitalization of around EUR 4.194 billion, giving the company the highest equity value among SDAX members at that time. This means that 1&1 alone accounts for roughly 4.6 percent of the index’s total market value, a weight that can materially influence index performance when the share price moves.

In the same SDAX snapshot, the index had gained 4.51 percent since the beginning of 2026, while its yearly high stood at 19,325.96 points and the low at 15,733.78 points per the finanzen.ch data as of September 16, 2026. For holders of 1&1 stock, this index trajectory forms an important backdrop: a large-cap SDAX constituent with a high weight tends to amplify both positive and negative sector trends in German small and mid caps.

Latest available fundamentals as historical reference

The most recent full-year reporting framework for 1&1 that is visible in the current search set is the 2025 annual report, which covers fiscal year 2025 and is made available as a German-language PDF. According to Sustainabilityreports.com, this document is classified as an annual financial report for the fiscal year 2025 and serves as the primary compilation of the company’s revenue, earnings and cash-flow figures for that year. While the detailed numbers are not exposed in the snippet, the report’s scope confirms that it contains the full set of income-statement and balance-sheet metrics relevant to 1&1’s operations.

Because fiscal year 2025 ended within 24 months of September 16, 2026, these annual figures are still suitable as a historical benchmark, but they no longer represent the latest interim performance in 2026. Investors therefore typically use the 2025 data to compare margins, revenue and profit trends with more recent trading indications, even if the exact revenue and net income numbers from 2025 must be retrieved directly from the report itself.

Investor focus on size and index role

The combination of a high SDAX weight and a multibillion-euro market capitalization gives 1&1 stock a special position among German small and mid caps. When the SDAX moves, 1&1’s share price can be a significant driver due to its weight of approximately 4.6 percent in the index’s aggregated market value as highlighted in the finanzen.ch overview dated September 16, 2026. For investors, this means that portfolio exposure to 1&1 is not only a bet on the company’s own fundamentals but also a lever within the broader SDAX performance.

At the same time, the historical fiscal-year 2025 report documented by Sustainabilityreports.com remains a key reference point for understanding the company’s profitability and leverage profile heading into 2026. While current-year interim figures are not yet visible in the present search results, long-term shareholders can use the 2025 baseline as a yardstick when new quarterly or half-year numbers for 2026 are published via the 1&1 investor-relations channels.

Stock price snapshot and trading venue

As a German issuer, the primary listing reference for 1&1 stock is Xetra in euros. As of September 16, 2026, the shares’ indicative market capitalization in the SDAX context is around EUR 4.194 billion per the finanzen.ch index overview, which implicitly reflects the prevailing Xetra quotation at that time. For investors, this valuation level underlines that 1&1 is not a micro cap but a sizeable player in German telecom and internet services, and that price movements in the stock can noticeably affect SDAX performance.