AIM is an exchange regulated venue featuring an array of principles-based rules for publicly held companies. AIM's regulatory model is based on a comply-or-explain option that lets companies that are floated on AIM either comply with.
Because AIM is an unregulated market segment, it escapes most of the mandatory provisions contained in European Union directives – as implemented in the UK – and other rules applicable to companies listed in the LSE. AIM believes self-regulation is pivotal to AIM’s low regulatory burden: companies seeking an AIM listing are not subject to significant admission requirements; after admission is granted, firms must comply with ongoing obligations which are comparatively lower to the ones that govern the operation of larger exchanges; and certain corporate governance provisions are not mandatory for AIM companies. Therefore, AIM-listed companies are often subject to manipulation by institutional investors. AIM-listed companies usually are only required to adhere to the corporate governance requirements of their home jurisdiction, which, as a practical matter, vary widely.
However, the regulatory requirements are more onerous than for private companies and AIM listed places are required to prepare audited annual accounts under.
Another important element of AIM’s model is the composition of its investor base. Although AIM-listed companies are not start-ups, most are small and highly risky. This may prove to be hazardous for unsophisticated investors who lack both the knowledge and resources to conduct proper inquiries into a firm’s prospects and activities, or even larger investors which lack strong internal control and risk management requirements. As a consequence, AIM’s investor base is largely composed of institutional investors and wealthy individuals.