Tin prices at the London Metal Exchange jumped 16.8% at the end of the session on Monday. The cost of the metal reached $29,625/t, up to $4,280. The three-month price ended at $24,385/t, which was a gain of $375 or 3.1%. That is a sign that the supply-demand situation is under strain as buyers tie up physical metal for immediate delivery. This development comes against a background of reports that China is stockpiling tin as part of its plan to become self-sufficient in semiconductors.