Only fairly recently has the law on securities regulation been subject to legislation, first and only on a framework basis on the national level and lately, but very profoundly on a European level as a consequence of the Financial Services Action Plan, that was carried out from 2000–2005. The ensuring legislation has produced a body of harmonised law that is highly detailed and mostly implemented verbatim in national law. The introduction of European Union (EU) law has complicated the traditional use of national law, partly by changing the reliance on preparatory works in traditional Nordic jurisprudence, partly by introducing new layers of legislation and new parties to the legislative process. The emerging federalisation of EU law is just entering a new and even more pronounced phase following the entry into force of the Lisbon Treaty. This article assess the development up to now by first presenting the distinct legal discipline of securities trading law and then exploring the problems arising from the rapid introduction of EU law within this narrow area of law.