What happens if somebody shorts two inverse levereged ETFs at the same time? http://finance.yahoo.com/q/bc?s=DIG&t=2y&l=off&z=l&q=l&c=dug http://finance.yahoo.

What happens if somebody shorts two inverse levereged ETFs at the same time? http://finance.yahoo.com/q/bc?s=DIG&t=2y&l=off&z=l&q=l&c=dug http://finance.yahoo.com/q/bc?s=DIG&t=2y&l=off&z... [Warning: Doing the above features similar dangers as a Martingale system.]