ETF is a closed-ended or open-ended fund?

ETFs are mostly open-ended funds. An open-end fund allows investors to participate in the markets and have a great deal of flexibility regarding how and when they purchase shares. In open-ended funds, shares are bought and sold on demand at their net asset value, or NAV. It is based on the value of the fund's underlying securities and is generally calculated at the close of every trading day.

Investors have the option to buy shares directly from the fund. The transactions in ETFs are made through the exchange. Investors receive the units in their Demat account. This is why it is mandatory to have a Demat account for investing in ETFs as opposed to their mutual fund counterparts.