Huh, shorting bear ETF's is actually not even such a bad idea given how shit their performance is. If you're generally short the market (stocks or futures) you could probably even upgrade your performance a bit by shorting the bear ETF's and transferring the proceeds into some unrisky interest carrying asset (like a swedish kroner or something).
Edit: You will obviously have to manage the trade carefully because the short position in the bear ETF increases while normal short positions decrease
