Reddit raiders swarm silver stocks as GameStop, BlackBerry retreat

(Reuters) - Shares of silver mining companies were swept up into retail investors' battle with Wall Street on Thursday, with some notching double-digit gains driven by social-media hyped stock buying.

Canada's First Majestic was among the biggest gainers, surging more than 30% after a report it won a reprieve on criminal tax fraud charges in Mexico.

Shares in video game retailer GameStop Corp, AMC Corp and Blackberry have soared as small investors, organizing on social media, have piled in and forced professional short-sellers to abandon their positions with heavy losses. Gains in those stocks were clipped Thursday amid trading restrictions.

But fresh posts on the Reddit discussion board WallStreetBets urged members to invest in First Majestic and the iShares Silver Trust ETF.

"Once you're done with GME - $AG and $SLV, the gentleman's short squeeze, driven by macro fundamentals," one of the posts said.

The number of short trades as a percentage of total traded volume for First Majestic jumped to 24.9% in the first half of January, from 21.1% in the second half of December, regulatory filings showed.

Trading in First Majestic's stock - traded under the same ticker as silver's periodic table symbol 'AG' - was briefly halted in New York while its Toronto-listed shares were last up 15%.

First Majestic said it was unaware of any material undisclosed information.

Todd Anthony, vice-president of corporate development, confirmed a media report that a judge in Mexico City declined to charge the Canadian mining company with criminal tax fraud.

He declined further comment.

Fortuna Silver Mines Inc rose 10% and London-listed Fresnillo Plc gained as much as 10% to top the FTSE.

Shares in Pan American Silver, Endeavour Silver and Silvercorp also rose.

Spot silver prices rose almost 7% before retreating.

"We are pleased to see the move in both the silver price and our share price today," said spokeswoman Simona Antolak at Wheaton Precious Metals, which rose as much as 6.5%.

Pan American and Endeavour declined to comment. Silvercorp did not respond to requests for comment.

(Reporting by Shariq Khan and Arundhati Sarkar in Bengaluru, Jeff Lewis and Maiya Keidan in Toronto and Ernest Scheyder in Houston; Editing by Frances Kerry and Sriraj Kalluvila)