This paper analyses the validity of the weak-form market efficiency, using the random-walk hypothesis for the six industrial base metals - copper, aluminium, zinc, nickel, tin and lead - traded at the London Metal Exchange. I analyse the behaviour of daily and weekly prices of the daily rolling...

There is a clear causal negative influence from margin requirements to market participation in futures markets. As margin requirements increase, market participants leave the metal futures market affected by the margin increase and apparently move into similar metal markets unaffected by the...