BBUS

Hi guys, this stock BBUS is a strong bear fund for the S&P 500 ETF
It says if the S&P 500 falls 1% than BBUS should go up 2-2.75%
and if the S&P 500 goes up 1% BBUS falls 2-2.75%

Yet a couple of days ago the S&P 500 fell 4% yet BBUS only went up 5.3%, according to their stats it should have gone up like 8-10%

anyone following this one, as someone who thinks the US markets could crash, I was looking at something that I could short the US market with, this looked perfect but if it barely follows the ETF managers formula, I don't know.

anyone got any thoughts on this one?

I know there is a BEAR ETF but that's only against aussie stocks, I think the US stocks will fall a lot more than ours will as the US market is so overvalued.