Like SPY options intraday volatility collapse kills naked calls.(spread ok)
Even weekly not easily to short against monthly calls. 0.10c weekly options can become a $ if the delta and theta goes along with it.
Because of daily re balancing ,ooozes a lot but 3 times leverage with XLF intra day is sweet if you catch it.
try buying FAS small quantity when it is over sold and sell weekly when it is overbought.
You can keep doing it again and again.
FAS may be same price after a week .but sold option premium is yours. worst come worst,your stock is called out (you made a 0/80c /$1 on 14$ stock.
Be prepared for a loss too as it will underperfom XLFa nd if it does not move.
same story as TNA,ERX,DRN,FAZ held longer term.