Silver smashed through $80 an ounce to an all-time high, extending a breakneck end-of-year rally powered by speculative trades and a persistent mismatch between supply and demand.The white metal spiked as much as 6 percent on a roller-coaster ride that took it to $84 an ounce early on Monday, then sent it plunging below the previous close, before it recovered. For all the latest headlines, follow our Google News channel online or via the app.A weaker dollar and rising geopolitical tensions have added to the appeal of precious metals during a bull run that has also taken gold and platinum to all-time peaks.Monday’s early momentum came after a comment by Elon Musk over the weekend that highlighted the growing investor frenzy around precious metals. Musk replied to a tweet on Chinese export restrictions by saying on X: “This is not good. Silver is needed in many industrial processes.”The Chinese measures are effectively a rollover of previous policies and were first announced by the