Just adding to Deustchmann's comments, another possible reason...

Just adding to Deustchmann's comments, another possible reason there maybe a very large project in Malaysia which is due to start soonish. Now soonish in the construction game maybe anything from tomorrow to next year.

What the project managers might have done is to secure the supply many months ahead just in case of tightness in the zinc supply market and have it stored at LME warehouse in Johor. Then they will buy it on "as needs basis" where you would then see the Onwarrants decline and the cancelled warrants increase to eventually the Zinc being shipped out.

I think though it looks very unusual and more of a one-off event. Next few days might tell the more the story.

Cheers