A computer-implemented method of purchasing or selling exchange-traded shares is performed by entering into a computer an order to purchase or sell exchange-traded shares on behalf of an investor on the secondary market through a broker, executing the order on the secondary market via one or computers, and updating account data of the investor in one or more account data computers to reflect the new number of exchange-traded shares held by the investor. The exchange-traded shares are exchange-traded shares that are associated with a single investment company that has issued one or more classes of shares that are bought from and redeemed with the single investment company at a net asset value, and one or more classes of shares that are listed for trading on a securities exchange and that are bought and sold at negotiated market prices. The shares that are bought and sold at negotiated market prices are the exchange-traded shares. The owner of any share of any share class has an undivided interest in the single investment company.