$ProShares Ultra Bloomberg Natural Gas (BOIL.US)$This fund has had an average annual decline of over 50% since its establishment 12 years ago. It was less than 16 when it was invested with 16,000 initially. Kold is slightly better, with 48 left from the initial investment of 415. Both are like meat grinders, with only a difference in speed. Has natural gas experienced such a drastic decline in the past 10 years? Even if natural gas only falls and does not rise, why have both inverse ETFs been declining?