Activist investors don't always prevail. But in the case of Brink's ( BCO), they're celebrating a victory. Following a round of activist activity, on Wednesday the company authorized a "Dutch auction" self-tender offer for up to 10 million of its shares, or about 17% of its outstanding stock. In midday trading, shares rose 4% to $50. Brink's is up 44% from a year ago. "The announcement supports the stock, reduces the share count and increases the earning per share. It's a shareholder value proposal," says James Clement, an analyst with independent research firm Sidoti & Co. Clement has a buy on the stock and a $61 price target. The tender price range will be $47.50 to $52.50 per share. There are 58.7 million outstanding shares. Between now and April 6, investors will be given the opportunity to tender shares to the company at specific prices within the range. Brink's will buy back stock at the lowest price necessary to redeem 10 million shares. If Brink's bought back 10 million shares at the midpoint of the range, it would cost $500 million. A provision of the tender offer unveiled Wednesday will permit the company to do more repurchases in the open market after the tender offer closes, bringing the total outlay up to $600 million. Anyone wondering why the Richmond, Va.-based security services company is being so generous with its cash should look at what hedge fund activism has achieved over the past three months. Among Brink's 20 largest investors, half were hedge funds as of Dec. 31, according to Thomson One Analytics. Collectively, they own about a third of the shares. The names are an A-list of activism: Pirate Capital, Steel Partners, Och-Ziff Capital Management, S.A.C Capital Management, Owl Creek Asset Management and Highbridge Capital Management.