Shares in a handful of smaller Australian silver miners surged as small-time traders bought en masse.
Argent Minerals jumped 60% while Investigator Resources was up 47%.
Coin-selling websites also reported unprecedented demand and flagged delays in delivering silver.
Silver rose by as much as 11% to $30 an ounce, its highest value since 2013.
What is going on?
It is the latest example of apparently small-time traders taking on big Wall Street hedge funds that hope to profit when the price of an asset or stock falls, but could lose heavily if it rises.
Tips posted on social media sites like Reddit say these so called “short sellers” are manipulating the markets.
And so the amateurs buy up the stocks or assets, driving up the price and inflicting losses on the big players.
It began in January when amateurs piled into loss-making retailer GameStop, causing its stock to spike more than 700% in a week.
But now the traders have turned their attention to silver – a far bigger market that they also allege is being manipulated.
What’s being said to stoke the speculation?
Reflecting the attitude of many of those swapping tips on the site, one user called RocketBoomGo urged fellow traders to “think about the Gainz” in a widely circulated post.
“If you don’t care about the gains, think about the banks like JP Morgan you’d be destroying along the way,” they added.
Again, the amateurs say they are justified in their actions because Wall Street firms are manipulating the silver market, allegedly.
However, reflecting the febrile atmosphere, some have alleged that the so called “Silver Squeeze” as it is being dubbed is secretly being coordinated by big Wall Street firms.
A large proportion of the silver market also exists “off-exchange”, meaning it can’t be bought and sold as easily online.
“Retail traders who are just following the herd and join the party late may accumulate huge losses and need to be more rational in their decisions,” Mr Sayed added.
Are the Wall Street giants on the ropes?
Despite what some retail traders had hoped, some of the biggest profiteers from last week’s market action were said to be Wall Street giants such as asset manager BlackRock and the private equity firm Silver Lake.
However, other big investors have been hammered by the trading frenzy.
Hedge fund Melvin Capital – which bet heavily that shares in GameStop would fall – lost 53% of its value towards the end of January, according to media reports.
The firm has since received commitments for fresh cash from investors, leaving it with around $8bn (£5.8bn) in assets, but that is still down from $12.5bn at the beginning of 2021, according to Reuters.
Regulators say they are monitoring the trend, while trading platforms have imposed restrictions on shares in GameStop and other companies caught up in the buying frenzy.
It sparked anger among amateur traders, who say they are just playing Wall Street at its own game, and several prominent US politicians and the billionaire Elon Musk have voiced their support.