BBUS, page-524

sigh
if you actually read and underestood the information in this thread you would be able to answer your own questions.
Dont feel bad because it is a bit hard

a. this is the BBUS thread not BBOZ
b. these ETFs arent shorts. they are "Bear funds" that achieve their short exposure by selling share index futures contracts – not by short selling the shares in the index
c. BBOZ uses the S&P/ASX 200 Index (SPI 200 futures), while BBUS sells S&P 500 Index futures. On the day you mentioned the futures were up, hence BBOZ down
d. for the ASX, and BBOZ, markets and futures are open at the same time as BBOZ trades. Therefor BBOZ tends to track the ASX movements.