Tin traders probably added to wagers that the metal will gain as the number of outstanding contracts climbed to the highest in more than three months at the same time as prices rose.
Open interest in London Metal Exchange tin futures climbed by 1,129 lots, or 4.3 percent, to 27,469 contracts in the week ended May 24, the highest level since Feb. 10, according to LME figures. Each lot represents 5 metric tons of the metal used in packaging or to join metals together. The benchmark contract for three-month delivery advanced 4 percent in the period.
An increase in open interest as prices rise suggests new long positions, or bets on higher prices, according to Macquarie Group Ltd.
Following are changes to market open interest for both LME members and their clients for the six biggest industrial-metals futures traded on the exchange. The figures were compiled by the LME.
Change in Price Change Open Interest (%) Aluminum 48,108 -1.9 Copper 6,414 -0.5 Zinc 0 -0.7 Lead 3,091 1.7 Nickel 3,786 -0.6 Tin 1,129 4.0