Silver continued a blistering rally on Friday, taking its gains to around 10% since messages began to circulate on Reddit on Thursday morning urging retail investors to pile into the market and drive up prices.

Silver's surge rubbed off on gold, which jumped as much as 2%.

The two were also helped by a softer dollar, which makes them cheaper for buyers holding other currencies, and falling stock markets.

Silver soared as much as 7% on Thursday after calls appeared on Reddit to buy silver mining stocks and iShares Silver Trust SLV , an exchange traded fund (ETF) backed by physical silver bars, in a GameStop-style squeeze.

Some silver traders covered short positions to avoid being caught by rising prices, while some mining stocks surged and trading of iShares Silver rose almost four-fold. 

Buying an ETF can bolster silver prices by increasing the number of shares in the fund and making its operator buy more metal to back them.

Analysts said they expected the rally to be short lived, with the size of the market making it far less easy to influence than companies like GameStop.

"We are confident that the influence of retail investors on silver will not last all that long, and that ultimately industrial and institutional demand will be the key factor in the longer term," Commerzbank analyst Eugen Weinberg said in a note.

By 01:43 p.m. EST (1843 GMT) on Friday, silver was up 2.5% at $27.04 an ounce, en route to its best weekly gain since mid-December, at more than 6%.

Standard Chartered analyst Suki Cooper said she expected solid demand for silver from investors and industry to lift prices towards $30 during the first half of 2021.

Spot gold, meanwhile, rose 0.6% to $1,851.01 an ounce. U.S. gold futures settled up 0.5% to $1,850.30.

But gold was on track for its worst January since 2011, something many analysts attribute to the recently strengthening dollar and increasing investor focus on assets that will benefit from economic recovery. 

Platinum rose 0.4% to $1,074.67, while palladium fell 4.6% to $2,227.25.

(Reporting by Asha Sistla and Arpan Varghese in Bengaluru, Peter Hobson in London; Editing by David Gregorio and Kirsten Donovan) ((Asha.Sistla@thomsonreuters.com; If within U.S. +1 646 223 8780; outside U.S. +91 80 6182 2808; Reuters Messaging: Reuters Messaging: asha.sistla.thomsonreuters.com@reuters.net))