A fund pools many people's money and invests it for them, so one purchase buys a slice of hundreds or thousands of holdings. The wrapper decides how you buy and sell that slice. An OEIC — like the older unit trust — is priced once a day at the value of what it holds, and you buy from and sell back to the fund manager. An ETF is a fund listed on a stock exchange, traded all day at a market price like a share. An investment trust is itself a listed company whose business is holding other investments.
The difference that matters most is whether it's open-ended or closed-ended. OEICs and ETFs are open-ended: units are created when money comes in and cancelled when it goes out, so the price stays close to the value of the holdings. An investment trust is closed-ended — it has a fixed number of shares — so its price is set by buyers and sellers and can drift well above or below what its holdings are worth. In the app, ETFs and investment trusts have tickers like any share. OEICs aren't listed, so the app can only track the ones its data provider covers.
Three ways of owning a pooled portfolio. The price mechanics are where they differ.
Educational content only. It is not personal financial advice.