Micro-blogging site Twitter is increasingly becoming an outlet for all manner of information, from celebrity exposes to embarrassing political faux pas. But traders glued to their Tweet Decks this week could have made good use of the wildly popular social networking phenomenon.

On Wednesday, shares in the mid-range US retailer JC Penney, which is listed on the New York Stock Exchange, jumped a whopping 10.5% following a Tweet issued by Marie Claire's famous style editor Nina Garcia.