# Article 6 — Conformance testing (Article 17(1) of Directive 2014/65/EU) **Commission Delegated Regulation (EU) 2017/589 · binding · OJ L 87, 31.3.2017 · dated 19 Jul 2016 [in force]** *In force · Commission Delegated Regulation (EU) 2017/589, OJ L 87, 31.3.2017 · Checked against EUR-Lex on 26 Oct 2026 · [Official source](https://eur-lex.europa.eu/eli/reg_del/2017/589/oj/eng)* 1. An investment firm shall test the conformance of its algorithmic trading systems and trading algorithms with: **(a)** the system of the trading venue in any of the following cases: **(i)** when accessing that trading venue as a member; **(ii)** when connecting to that trading venue through a sponsored access arrangement for the first time; **(iii)** where there is a material change of the systems of that trading venue; **(iv)** prior to the deployment or material update of the algorithmic trading system, trading algorithm or algorithmic trading strategy of that investment firm. **(b)** the system of the direct market access provider in any of the following cases: **(i)** when accessing that trading venue through a direct market access arrangement for the first time; **(ii)** when there is a material change affecting the direct market access functionality of that provider; **(iii)** prior to the deployment or material update of the algorithmic trading system, trading algorithm or algorithmic trading strategy of that investment firm. 1. Conformance testing shall verify whether the basic elements of the algorithmic trading system or the trading algorithm operate correctly and in accordance with the requirements of the trading venue or the direct market access provider. For this purpose the testing shall verify that the algorithmic trading system or trading algorithm: **(a)** interacts with the trading venue's matching logic as intended; **(b)** adequately processes the data flows downloaded from the trading venue.