ETFs by design are less volatile. However, many have stocks based on their market caps. It turns out most of them are rocket stocks such as Apple, Amazon... ETFs based on smaller caps do not have this risk. However, I prefer contra ETFs now as the market is risky to me.
Using SPY (simulating S&P 500) as an example, it should be .2% if the selection is not weighted according to the market cap. For SPY, the first stock Apple is 4% and about 2% for the next 3 stocks. They are all rocket stocks.