The conclusion of the saga removes a stock overhang for Chevron and paved the way for the $53 billion deal to close immediately.

Chevron Corp. has prevailed in a 20-month fight to buy Hess Corp. for $53 billion, overcoming a challenge by arch rival Exxon Mobil Corp. that was unprecedented in the modern history of Big Oil.

After nearly two years of legal limbo and uncertainty, Chevron (NYSE:CVX) has officially sealed its $53 billion acquisition of Hess Corp.and merger arbitrageurs are walking away with a big win. Top hedge funds like Citadel Advisors,