If the new world runs out of steam, the new new world of developing markets can get along fine on its own. That is the decoupling thesis in a nutshell. This week, though, few were buying it.

The lock-step bounce in global securities markets after the Federal Reserve's emergency rate cut yesterday underscored that decoupling has yet to take hold in financial markets at least. What are other assets telling us? Commodities, in particular, are darlings of decoupling enthusiasts, enamoured with China's seemingly unshakable development.