Agree Timely1 regarding the liquidity that short term traders provide.
It's not possible to short BMB, at least not as far as I'm aware. Happy if you can point me in the direction of a provider that would enable investors to short BMB, GFT don't. I've checked the ASX Short Sales listing a number of times with no sign of BMB being shorted on each occasion that I've looked.
http://www.asx.com.au/data/shortsell.txt
BMB Price at posting:
18.0¢ Sentiment: Buy Disclosure: Held