SILVER and PLATINUM PRICES sank overnight before rallying in volatile London and US trade on Thursday as base metals copper and tin also hit sharp volatility after US President Trump decided not to impose tariffs on imports of what are now deemed to be "critical minerals".

Imposing instead a 25% import tariff on "certain advanced computing chips", Trump last night ordered Secretary of Commerce Howard Lutnick to negotiate purchase agreements for foreign-processed critical minerals by setting "price floors" to protect and encourage domestic US production.

Silver bullion − having lost the threat of US tariffs which drove record US silver stockpiling last year − plunged 8.0% at the start of Asian trade, dropping from a fresh record price above $93.75 per Troy ounce for London settlement, down as low as $86.25 before rallying back above $90.

Fellow US critical mineral platinum also sank, erasing this week's previous gains with a 6.0% drop to $2257 per ounce before rallying to $2385, while copper plunged 3.1% and tin lost almost 5% from yesterday's fresh all-time highs.

Gold also dropped and rallied, trading back above $4600 after losing 1.5% to $4582 per ounce overnight.

That was a new record high for gold this Monday. This morning's low in silver was a new record high on Tuesday.

"The immediate heat may be off silver, but we can't expect the tightness [in trading conditions] to ease dramatically, especially as it's now tight in Asia also," says analyst Rhona O'Connell at brokerage StoneX.

Another 40 tonnes of silver had already left CME-approved warehouses around New York City on Tuesday, latest data show, taking the total holdings down to 13,510 tonnes.

That's almost 1/5th below the peak reached in September, and almost 10% smaller than early November, when the US Geological Survey added silver to its list of "critical minerals".

"More may well have come out from elsewhere," says O'Connell, "and it is not a given that it has all come into London," where silver stockpiles ended December at a 3-year high.

Giant silver-backed ETF the iShares Silver Trust (NYSEArca: SLV) shrank 0.5% in size on Wednesday but set a fresh record by value above $47.5 billion − matching almost 30% of giant gold ETF the SPDR Gold Trust (NYSEArca: GLD) − as the industrially-useful precious metal hit new all-time highs.

"Following silver’s exceptional price gains, efforts to reduce silver usage in the industrial space are expected to accelerate," says analysis from specialist consultancy Metals Focus. "[But] the impact of these demand losses is likely to be mitigated by continued strong investment demand."

"Millions of silver spectaculars are selling as prices go up," says personal finance guru Robert 'Rich Dad' Kiyosaki, warning that "The sellers will crash the silver market."

"There will be a major pull back before it begins climbing again. I am planning on trading my silver for gold," says Kiyosaki, who − in a post on his YouTube channel last January − said that he was then selling his silver to buy Bitcoin.

December already saw "a record, relentless deluge of profit-taking in silver," says US bullion wholesaler and retailer FideliTrade, with a record number of customer sell orders "overwhelming...exceptionally light" buying volumes in retail silver bars and coins.

Yesterday's peak in spot silver prices broke the $92.50 stop-loss level for any clients of Canadian brokerage TD Securities who followed its tip last Wednesday to sell silver short at $78 per ounce, forecasting a "dramatic reversal in silver's devilish blow-off top."