That’s why those wankers get paid so much

Pardon me while I go on an off-topic rant. Who can understand the machinations of global financial markets? Can someone, anyone, please explain to me why it is that when the US financial system has its worse week since 1929, while the effect on Australia is relatively mild due to our stronger economy and well-capitalised banks, the Australian dollar tanks against the US dollar? I have a personal stake in this argument as I have a couple of children about to embark on a gap-year sojourn across the US and their dad is unable to explain why their trip just got a hell of a lot more expensive. If the US economy is in the toilet, why has its currency strengthened against the A$? All I can say is that if stockmarket and investment gurus can understand this, that must be why they make such obscene fees while intelligent, passionate, caring schoolteachers, etc. are driving around clapped-out Holdens. Feel free to give an Economics 101 lesson via the comment facility.