Rural/Metro Corporation (NASDAQ: RURL) shares leaped 36.3% to $17.11. More than four million shares changed hands in the first hour, overwhelming a full-day average around 91,000, after it announced it has entered into a definitive agreement for the acquisition of the Company by the private equity firm Warburg Pincus in an all-cash transaction.

Verigy Ltd. (Nasdaq: VRGY) was among the volume leaders in the early going Monday, trading in 9.1 million shares, compared to a full-day average of 1.2 million. Share prices were up 0.4% to $14.23, amid stories Advantest was to buy Verigy for $1.1 billion.

Fuqi International Inc. (Nasdaq: FUQI) shares fell 5.7% to $3.17. Share volume topped 883,000, trumping its average of 568,635. The Chinese jewelry company again delayed the filing of its restated 2009 results, citing an internal investigation of cash transfers.