Blame it on the Siberian winter. The price of nickel, a metal used in stainless steel and the U.S. coin, has soared 80% since August, in part because of weather-related production shortfalls at the huge Norilsk refinery on the remote Russian tundra. Add in surging demand and a scrap shortage, and you have a mecca for speculators. On Feb. 6, a correction blew off some froth, sending prices down 11%. But after more retrenchment, analyst Vahid Fathi of Kemper Securities expects a buying opportunity. By next year, he predicts, prices will be 25% to 30% higher.