RPT-COLUMN-London aluminium hit by flash squeeze even as stocks surge: Andy Home

(Repeats July 6 column with no changes. The opinions expressed here are those of the author, a columnist for Reuters)

* LME Aluminium stocks and spreads: https://tmsnrt.rs/31QegmK

By Andy Home

LONDON, July 6 (Reuters) - The London aluminium market was rocked by a short but severe squeeze last week.

Short-position holders had to cough up as much as $20 per tonne to roll their positions a day.

This may seem strange given the world is apparently once again awash in aluminium.

London Metal Exchange stocks (LME) have surged by 68% from a mid-March low of 967,325 tonnes to 1,624,775.

The increase in visible stocks in the market of last-resort delivery is likely being matched by a bigger build in the statistical shadows.

But the aluminium market has learnt before that appearances of surplus can be deceptive when it comes to LME spreads.

As shorts just found out to their cost. The flash squeeze has passed but it's a sign that the stocks financing business is on the rise again.

It also places the spotlight back on the LME itself, given it has just spent a decade reforming its delivery network after the last wave of surplus aluminium in the wake of the financial crisis.

SHORT BUT BRUTAL

The full force of last week's squeeze hit short position-holders trying to roll daily positions across the LME's "tom-next" spread.

"Tom-next", the shortest-datest of all timespreads in the exchange's labyrinthine forward trading structure, usually defaults to a small contango.

There was a brief bout of turbulence at the end of June but nothing to compare with the second half of last week when "tom-next" traded out to $20 backwardation on Friday morning, the widest it's been since 2012.

That wasn't a rogue print either. A total 140 lots (3,500 tonnes) traded at that level with another 497 lots transacted at a backwardation of $19.

Shorts appear to have misjudged how much liquidity was available with one dominant long position holder accounting for 30-40% of available LME stocks. Additional cash positioning lifted that ratio to 40-50%, not enough to trigger the exchange's mandated lending caps but still a big position, equivalent to up to 730,000 tonnes.

Cash-date pressure tightened up the whole aluminium forward curve. The benchmark cash-to-three-months time-spread was last week trading at less then $20 contango, compared with double that as recently as May.

The squeeze has now passed. "Tom-next" has reverted to small contango and the cash-threes contango has collapsed back out to $31.25 as of Friday's close.