A extreme example
a stock price 10
a 2x ETF based on this stock,
one day price is up to 15, 50% gain, your 2x ETF 100% gain.
next day stock price drop to 10, 50% loss, 2x ETF 100% loss = 0
a stock price 10
a 2x ETF based on this stock,
one day price is up to 15, 50% gain, your 2x ETF 100% gain.
next day stock price drop to 10, 50% loss, 2x ETF 100% loss = 0