Find that chart with an overlay of FAS and a good financial index. Some things in the past are patterns for future events, others never recur. That chart is one that can never repeat.
Example: On March 6th one share of Faz @ $104.07 plus one share of FAS @ 2.64 = total cost of $106.71 per share to hold equal shares of both ETFs. Today it would cost you only $14.47 combined to own equal shares of both funds.
This should give you an idea of how fast money evaporates with leverage.
If there was the slightest possibility of a repeat. You would not be able to buy either fund. Traders would buy all the shares, hedge one with the other, and wait for combined value to pass $100 again.