What if, post 2008, a bank or hedge fund wrenched its money out of risky markets and poured it into anything that was likely to be a store of value through the storm?

What if, as markets roiled, many such investors found they could make an attractive margin by borrowing cheap money to buy cheap aluminium, hedging forward sales at a higher price on the LME, and delivering the material back on to the exchange as the contracts became prompt?

What if, in their eagerness to secure physical metal in carry trades, banks and hedge funds paid handsome premiums to aluminium producers and traders?

But what if the stable, attractive and knowable return afforded by the aluminium carry-trade was subject to unforeseen regulatory risk?

What if they were speculating that they would be able to recoup a substantial portion of that unhedged input cost when delivering the metal back into warehouses or the physical market?

What if they did not consider the possibility that, for example, US legislators might order banks to give up all their physical commodity assets?

(Unthinkable a few months ago, but a prospect that will have crossed a few people’s minds since July.)

What if you got into the market at a duty-paid premium of around $300 per tonne in December or January, and now premiums are at least $45 per tonne lower?

(There is little prospect of them returning to those levels, though they may have firmed for the moment.)

What if physical buyers wait till they are running on hope to see when premiums will fall without the warehouses’ support?

For the moment the market appears to be well-supported, but what if spot and contract premiums eventually fall steeply?

Where will financiers be if they do?

What if treasury departments, who are monitoring this closely, don’t like the exposure they see?

What happens to the aluminium price if the controlled reductions of positions that are going on at the moment become more desperate?