I've done my calculation and based on the BBUS gearing being...

I've done my calculation and based on the BBUS gearing being 2.5% increase on the S&P falling 1%.
A fall of 50% on the S&-500 would equate to a 250% return on your BBUS hedge.
See calculations below which show 2.5% compounding from a starting point of $10k
Each line represents a 1% fall in the S&P-500.

With these numbers you can calculate what your hedge weight should be to cover your portfolio (in theory).
E.G. if you have a $300,000 portfolio and you want to cover it for a 50% fall in value You'd have to buy $42k in BBUS. this would cover you for a loss of $147,000 on your portfolio.
If the market goes the other way and rises and your $42k investment went to zero you would need the value of your portfolio to rise by 14% to cover your hedge E.G $300,000 + 14 % = $342,000. (however it is unlikely your BBUS would lose all value on a 14% ASX rise).
This is all dependent on holding the right stocks, but you get the idea.

The ultimate investment would be to have stocks that fair better in a fall, but the risk with that is they may not rise 14% if the market goes up.
I'd be interested if Troydt comes up with the same numbers?
It could also be possible that the fund could go up much higher that 2.5% to 1% gearing, but it's a good way to calculate cover.

$10000 + 2.5% = $10250 S&P500 falls 1%

$10506

$10769

$11038

$11315

11597

11886

12184

12488

12800 S&P500 falls 10%

13120

13448

13785

14129

14482

14845

15216

15596

15986

16386 S&P500 falls 20%

16795

17214

17645

18086

18538

19002

19477

19963

20463

20974 S&P500 falls 30%

21499

22036

22587

23152

23730

24323

24931

25554

26193

26847 S&P500 falls 40%

27519

28206

28912

29634

30375

31135

31913

32711

33529

$34367 S&P500 falls 50% = 250% return on $10000