Shares in Finland-focused miner, Irish-listed Karelian Diamonds closed up a stonking 450pc yesterday in heavy volumes for the stock.
The record gain was a delayed reaction after Karelian said on Wednesday that it had it received a positive technical report from the Geological Survey of Finland on a diamond discovery originally announced on January 31.
The results indicate the presence of potentially rich kimberlite on the site. The shares, a so-called penny stock, closed up 450pc at 2.2 cents each in Dublin.
That was a massive outlier in generally weaker markets. The Iseq index closed down 0.20pc at 6,543.53.
Across Europe, declines in banks and miners sent indices lower for the first time in eight days, while investors also assessed disappointing corporate outlooks.
The Stoxx Europe 600 Index lost 0.4pc at the close.
Nestle, Cobham Plc and NN Group NV were among shares that declined after their earnings updates. The equity benchmark had extended a one-year high earlier in the week, buoyed by expectations of higher borrowing costs in the US as well as higher inflation globally.
On Thursday though, Stoxx 600 miners fell from their highest level since 2014, tracking declines in copper prices. Lenders halted a three-day winning streak.
NN Group, the Dutch insurer buying competitor Delta Lloyd NV, fell 7.6pc after reporting that fourth-quarter profit declined by almost 60pc.
US stocks meanwhile fell from record levels as financial and energy companies slumped while tech stocks erased earlier gains.
The Dow Jones Industrial Average lost 19 points to 20,593, breaking the longest streak of gains since September 2013.