What we don’t know (but will know very soon) is what derivatives have to be unwound due to a Russian default.
It could be anything from a nothingburger to a total worldwide economic collapse where central bank and government intervention is unable to rescue enough counterparties to save the system.
The wackiness of the international financial system is that nobody knows where all the bodies are buried any more.
Ah NO. Russian debt is not that big in the grand scheme of things.