The number of shares in open-end and closed-end mutual funds remains constant over time, while the number of shares in an ETF fluctuates.

Trades in open-end and closed-end mutual funds are executed once a day at the net asset value, while ETFs can be traded at the market price any time the market is open.

Open-end and closed-end mutual funds typically trade at or very close to their net asset values, while ETFs typically trade at prices lower than their net asset value.