RSAAKKS

Clearing Up Misconceptions About Leveraged ETFs

"If you invested in a leveraged ETF over a period of months and the market went down 20%, a 2x short leveraged ETF wouldn’t go up exactly 40%."
Yes, that part is clear and if market went down 20%, the 2x ETF will be (or shoudl be) down perhaps 32-36?% or some such fugure. Problem that I cannot comprehend is when oil goes up 5 fold and the leveraged ETF goes down. That is the part no logic can expalin, but has actually happened. Just look at the ETF and oil prices in 2008-2009.
Secondly, if these instruments reset everyday, why not just make them good for a day only, i.e., at the end of the day, fund automatically sells at NAV--period. You want to play it, buy it every day after market opens.