LME 3-month zinc at $3,645/ton, +$130 on London PM kerb on follow-through consumer buying, says trader at major Japan house; tips it to reach $3,800 later as consumers take opportunity to buy after sharp drop since start of week from selling related to rebalancing of DJAIG index. However, volatility to continue with swing back to $3,500 possible if strong fund selling emerges in London.