For the purposes of this Directive, and subject to Article 2, UCITS shall be undertakings: -the sole object of which is the collective investment in transferable securities of capital raised from the public and which operate on the principle of risk-spreading, and -the units of which are, at the request of holders, re-purchased or redeemed, directly or indirectly, out of those undertakings' assets. Action taken by a UCITS to ensure that the stock exchange value of its units does not significantly vary from their net asset value shall be regarded as equivalent to such re-purchase or redemption. Such undertakings may be constituted according to law, either under the law of contract (as common funds managed by management companies) or trust law (as unit trusts) or under statute (as investment companies). For the purposes of this Directive 'common funds' shall also include unit trusts., Euroopa Majanduspiirkonna lepinguriigis (edaspidi lepinguriik) tunnustatud fond, mis vastab Euroopa Liidu Nõukogu direktiivis 85/611/EMÜ siirdväärtpaberitesse ühiseks investeeringuks loodud ettevõtjaid käsitlevate seaduste, määruste ja haldusnormide kooskõlastamise kohta (EÜT L 375, 31.12.1985, lk 3–18) (edaspidi investeerimisfondide direktiiv) sätestatud nõuetele ja mille osakuid või aktsiaid võidakse avalikkusele pakkuda kõikides lepinguriikides