Forbes has tracked the largest listed companies globally for quite some time.
Just looked at the latest SEP quarter and 8 out of 10 are good ol USA (2 Chinese = Ali and 10c), and the top 6 all USA (you'll know the names)
Oil would also help the Chevrons and Exxons in better times.
The last time an Oz company made top 10 was BHP back in last Q 2012.
US entrepreneurship something to be reckoned with.