????雖然年中曾出現一輪拋盤，但美國股市今年總體表現強勁。截至12月月中，標準普爾500指數（S&P 500）上漲了近15%。

????《財富》美國500強公司今年也表現出色，幾乎有80%的公司股價都呈現正增長，約60%實現了兩位數的增長。《財富》美國500強公司2012年十大牛股中，有8家公司的股價實現了三位數的增長。

????十大牛股包括美國銀行（Bank of America）和惠而浦（Whirlpool），這兩家公司都得益于美國房地產市場的回升。很多煉油公司也取得了漂亮的漲幅。

????以下是《財富》美國500強2012年漲幅最大的十只股票（倒序排列），數據計算是根據12月7日的收盤價。

????Despite another mid-year sell-off, the stock market has logged a strong performance this year, with the S&P 500 up nearly 15% through mid-December.

????Fortune 500 companies?have had a banner year too, with almost 80% of those companies posting gains. Roughly 60% have enjoyed double-digit percentage increases. And of the top 10 best performers among the Fortune 500 companies, eight have had triple-digit jumps.

????Among the best performers were?Bank of America?(BAC,?Fortune 500)?and?Whirlpool(WHR,?Fortune 500), which are benefiting from the rebound in the housing market. A number of oil refiners have also booked stellar gains.

????Click through to see the top 10 Fortune 500 performers (counting down from good to great), based on their closing prices as of Dec. 7.

第10名 馬拉松原油公司

股票代碼：MPC

今年迄今股價漲幅：88%

市值：213億美元

《財富》美國500強排名：31

????馬拉松原油公司（Marathon Petroleum）于2011年6月從馬拉松石油公司（Marathon Oil）剝離出來，主營石油精煉、銷售和運輸。公司在伊利諾伊州、俄亥俄州、密歇根州、路易斯安娜州、肯塔基州和得克薩斯州都設有煉油廠。另外，公司在美國中東部擁有龐大的零售網絡。

????迫于維權投資者Jana Partners的壓力，馬拉松原油現在已將管道業務剝離出去，MPLX LP于今年10月完成上市。自那以來，這家有限合伙公司的股價漲了41%。在Jana Partners的敦促下，馬拉松原油公司也同意在2月份回購20億美元的股票。

????這家原油公司還出資25億美元收購了英國石油（BP）的得克薩斯城煉油廠，該廠2005年的一場爆炸事故曾造成15名工人死亡。該公司表示，這家煉油廠現在已經安全了。分析人士相信，這將給馬拉松原油提供更多空間，在快速增長的墨西哥灣地區進行拓展。

????最大的問題是需求。假如經濟放緩壓低油價，馬拉松原油公司的股票將在2013年遭遇沖擊。

#10 Marathon Petroleum

Ticker:?MPC

YTD stock performance:?88%

Market cap:?$21.3 billion

Fortune 500 rank:?31

????Spun out of?Marathon Oil?(MRO,Fortune 500)?in June 2011,?Marathon Petroleum?(MPC,?Fortune 500)refines, markets, and transports oil through refineries in Illinois, Ohio, Michigan, Louisiana, Kentucky and Texas. The company also has a large retail presence in the Midwest.

????Under pressure from activist investor?Jana Partners, Marathon Petroleum spun off its pipeline operations, taking?MPLX LP?(MPLX)?public in October. Since then, shares of that limited partnership have increased 41%. At Jana Partners' urging, Marathon Petroleum agreed to buy back $2 billion worth of shares in February as well.

????The petroleum company also spent $2.5 billion to acquire?BP's?(BP)?Texas City refinery, the site of a 2005 explosion that killed 15 workers. The company said the refinery is safe now, and analysts think it will give Marathon more room to expand in the growing Gulf Coast region.

????The biggest concern is demand. Should a slowing economy dampen oil prices, Marathon Petroleum could take a big hit in 2013.