This Regulation supplements Directive 2014/65/EU (MiFID II) by specifying delegated acts and detailed rules to ensure coherent application of authorisation, market transparency and integrity. It clarifies scope and definitions for wholesale energy contracts that must be physically settled, oil and coal derivatives, currency derivatives and spot contracts (including non‑deliverable forwards), contracts on underlying variables, the distinction between generic and personal investment advice, the definition and thresholds for systematic internalisers, and the definitions and limits for algorithmic trading, high‑frequency techniques, smart order routers and direct electronic access.

It establishes harmonised organisational and conduct requirements for investment firms, regulated markets and data reporting service providers on compliance, risk management, outsourcing, conflicts of interest, remuneration, personal transactions, investment research, underwriting and placing, client information, costs disclosure, suitability and appropriateness assessments, written client agreements, record‑keeping, reporting and best execution. It also addresses SME growth markets, market‑data provision by APAs and CTPs on a reasonable commercial basis, consultation with ESMA, respect for fundamental rights and data‑protection rules, and aligns its application date with Directive 2014/65/EU.