"What the project managers might have done is to secure the...

"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."

Doesn't seem a clever way of doing it. If the project manager wants certainty of supply then all of it should be on cancelled warrant. Otherwise it could disappear and the zinc has to be shipped from elsewhere, adding to costs.