Systems and methods are disclosed for managing and trading an investment fund having a portfolio including any combination of financial instruments and cash and having a general class of fund shares tradable in a secondary market. In the disclosed processes, assets enter and are removed from the investment fund through an exchange-traded fund share creation and redemption process governed by a set of rules. An intra-day fund share net asset value proxy based on a fund portfolio is distributed through electronic quotation vendors during the trading day at a specified interval. Notices of intention to create or redeem shares of the redeemable share class received by a specified time result in implementing the creation or redemption of shares at a net asset value determined after the notices are received. These features protect ongoing investors in the fund from costs of fund share trading by entering and leaving shareholders.