A leveraged ETFs (exchange-traded funds) are a special type of ETF that attempts to achieve returns that are more sensitive to market movements than a non-leveraged ETF. Leveraged index ETFs are often marketed as bull or bear funds. A bull ETF fund might for example attempt to achieve daily returns that are twice times (there are triple funds as well) more pronounced than the Nasdaq 100, the Dow Jones Industrial Average or the S&P 500 indexes. A bear fund (inverse fund) on the other hand may attempt to achieve returns that are twice times opposite to the daily index return, meaning that it will gain twice the loss of the market.
Naked options trading is very risky - many people lose money trading them. It is recommended contacting your broker or investment professional to find out about trading risk and margin requirements before getting involved into trading uncovered options.