Both Nigeria and the UK have recently overhauled their securities regulation regimes, Nigeria by its Investment and Securities Act 1999 (ISA 1999) and the UK by its Financial Services and Markets Act 2000 (FSMA 2000). The FSMA 2000 has resulted in a single, cross-sectoral regulator, the Financial Services Authority (FSA). It regulates the whole of the UK financial services sector: investment business, banking and insurance. This Act is the culmination of an evolutionary process which began with self-imposed so-called “self-regulation” (in particular, of the London Stock Exchange in the 19th century) and led to self-regulation within a statutory framework under the Financial Services Act 1986. The main umbrella regulator under the 1986 Act was the Securities and Investments Board, the SIB, a registered company limited by guarantee, to which statutory powers were (revocably) delegated by the Government. But the day-to-day regulation of investment businesses was in fact undertaken by a number of self-regulatory organizations (SROs), which were “recognized” and overseen by the SIB. This complex institutional structure proved unsatisfactory and the FSMA 2000 now directly vests all regulatory powers in a single regulator, the FSA. In status the FSA is the SIB re-named but it now has extensive, directly conferred, statutory regulatory powers over the whole financial services sector.