# Article 1 — Definitions **Commission Delegated Regulation (EU) 2025/1156 · binding · OJ L, 2025/1156, 3.11.2025 · dated 12 Jun 2025 [in force]** *In force · Commission Delegated Regulation (EU) 2025/1156, OJ L, 2025/1156, 3.11.2025 · Checked against EUR-Lex on 26 Oct 2026 · [Official source](https://eur-lex.europa.eu/eli/reg_del/2025/1156/oj/eng)* For the purposes of this Regulation, the following definitions shall apply:\ **(a)** ‘market data client’ means the natural or legal person who signs the market data agreement and is invoiced for the market data fees; **(b)** ‘market data’ means the information market operators and investment firms operating a trading venue, approved publication arrangements (‘APAs’), consolidated tape providers (‘CTPs’) and systematic internalisers publish in accordance with Articles 3 and 4, Articles 6 to 11a, and Articles 14, 20, 21, 27g and 27h of Regulation (EU) No 600/2014; **(c)** ‘delayed market data’ means market data made available 15 minutes after publication, pursuant to Article 13(2) of Regulation (EU) No 600/2014; **(d)** ‘market data provider’ means a market operator or an investment firm operating a trading venue, an APA, a CTP or a systematic internaliser that is engaged in a commercial activity of market data dissemination to clients; **(e)** ‘total costs’ means all the costs sustained by the market data provider directly related to the production and dissemination of market data; **(f)** ‘operating profit’ means the income earned by the market data provider, subtracting the total costs from the revenues generated by the production and dissemination of market data; **(g)** ‘market data agreement’ means any agreement between the market data provider and the market data client for the provision of market data and reflecting the information and fees disclosed in the market data policy; **(h)** ‘market data policy’ means one or more documents from the market data provider, containing information on the provision of market data, in accordance with Chapter V of this Regulation; **(i)** ‘per client fee’ means a model of charging fees for market data which enables clients to avoid multiple billing in case market data has been sourced through multiple market data providers or redistributors. **CHAPTER II — CALCULATION OF TOTAL COSTS AND MARGINS OF MARKET DATA**