Mutual fund with a set limit of shares available to investors or a set limit of monies or stock-types. Transactions in the shares of such funds are based on their market price . If the share price is above the offering price, it is at a premium. If the share prices is below the offering price, it is at a discount . The fund’s net asset worth, or NAV, is based on the number of shares times the current price . These shares may also traded on the stock exchanges. Called unit investment trust , or UIT, in the US and called unit trust in the UK and elsewhere. Contrast this to open-end mutual funds that continuously have new shares issued in response to investor demand.