automated trading EU MiFID II compliance retail trader rules

What MiFID II Article 17 says

MiFID II Article 17 requires investment firms engaged in algorithmic trading to:

• Maintain effective systems and risk controls to prevent erroneous orders
• Test trading algorithms before deployment
• Maintain real-time monitoring capability
• Have kill-switch functionality
• Report algorithmic trading activity to their national competent authority (NCA)
• Comply with RTS 6 (Regulatory Technical Standard 6) on organizational requirements

These requirements are designed for professional firms running high-speed, high-volume algorithmic trading on regulated exchanges. They are not designed for retail investors using simple rule-based systems through a broker API.

Who is an "investment firm" under MiFID II?

Under MiFID II, an investment firm is a legal person whose regular occupation or business is the provision of investment services or activities. A retail individual trading their own account through a licensed broker is NOT an investment firm — they are a client of an investment firm (the broker).

This distinction is fundamental: the retail trader using the Nordnet nExt API is a client of Nordnet. Nordnet is the investment firm subject to MiFID II Article 17 compliance. The retail trader is not.

What retail traders DO need to comply with

Retail traders using automated strategies must comply with:

• Market Abuse Regulation (MAR): applies to all market participants. Automated strategies must not be designed to manipulate prices, create false impressions of volume, or engage in other prohibited market manipulation. This applies regardless of whether you are a retail trader or investment firm.
• Broker terms of service: automated trading via API must comply with the broker's specific API usage terms. Nordnet, for example, has rate limits and prohibited activities in its nExt API terms.
• National tax law: automated trading generates taxable events like any other trading.

ESMA supervisory briefing on algorithmic trading (February 2026)

ESMA published a supervisory briefing on algorithmic trading in February 2026. This briefing is addressed to national competent authorities (NCAs) and investment firms — it is not a new obligation for retail traders. It covers areas such as co-location, direct market access, and high-frequency trading — all institutional-level topics.

Practical summary for Nordic retail traders

If you are a retail trader using an automated strategy through Nordnet, Saxo Bank, IG, or another licensed broker: you are not subject to MiFID II algorithmic trading compliance requirements. Use a licensed broker, follow their API terms, do not use your algorithm to manipulate markets, and report your gains to your national tax authority. That is the extent of compliance required for retail automated traders in the EU.

TRION was built around an honest validation sequence rather than a promise. It is a paper-only research and validation workstation: you describe a strategy idea in plain English, read the compiled logic line by line, and backtest it against real stored market data. When a metric cannot be computed honestly, TRION shows "N/A" instead of inventing a number.

TRION does not place real orders, does not connect to a broker, and does not promise profit. The current beta is simulation-only and paper-only. AI assists with drafting and explanation; it does not approve, activate, or execute anything. Humans make every decision.