It's important to understand that TS's OTC short Ni positions...

It's important to understand that TS's OTC short Ni positions with its bankers and any need for TS to find the cash to pay for magin calls relating to adverse movements in their NP bet is a matter between themselves. JPM electing to extend credit in exchange for suitable security from TS is what bankers do. JPM should by now be acutely aware of the risks they are taking and one would like to think they have obtained sufficient lending security buffer.

To the extent that JPM has laid off its risk by hedging in LME futures means that it's JPM, not TS, who is on the hook for the associated LME margin calls, which JPM will have covered by now.

The real question/issue now is whether the TS/JPM bet against rising NPs is an accurate reading of the big picture or a massive misjudgment of a fundamental shift in Ni pricing dynamics.