Exxon Mobil Corporation (NYSE:XOM), Apple Inc. (NASDAQ:AAPL), Google Inc (NASDAQ:GOOG), Berkshire Hathaway Inc. (NYSE:BRK.A) (NYSE:BRK.B) and Wal-Mart Stores, Inc. (NYSE:WMT) are now the five biggest companies in the world according to market value. Data compiled by Bloomberg shows that this hasn’t happened in eight years.

Apple and Google Logos

The Chinese company PetroChina Company Limited (NYSE:PTR) (HKG:857) (SHA:601857) and two other Chinese stocks were in the top five last year, but PetroChina is now at number six—the top spot held by a Chinese company. Wal-Mart Stores, Inc. (NYSE:WMT) pushed the Chinese company out of the top five with its 4.6 percent gain, which pushed its market value up to $258 billion.

Berkshire Hathaway Inc. (NYSE:BRK.A) (NYSE:BRK.B) has risen 17 percent so far this year to a market value of $259 billion. Apple Inc. (NASDAQ:AAPL)’s market value has fallen slightly, pushing it below Exxon Mobil Corporation (NYSE:XOM) for the third time this year, but it still remains in the top five.

Google Inc (NASDAQ:GOOG) has also rallied this year, rising 13 percent, which pushed its market capitalization to a record high of $278 billion last month. The company’s stock has risen 4.4 percent since last week’s report indicated that profits were above the predictions of analysts.

Other U.S. companies which have posted big rallies this year include Lennar Corporation (NYSE:LEN), which is the third biggest homebuilder in the U.S. Last month its stock soared almost to the highest it has been in six years on the heels of its better-than-expected profit and 34 percent increase in orders. Also Mattel, Inc. (NASDAQ:MAT) jumped the most in three months on news of higher profits and revenues than expected.

Of the top 50 companies in the world according to market value, 26 of them are now U.S. companies. According to Bloomberg data, it’s on track to hitting the highest annual total since 2005. At the beginning of the economic downturn in 2007, that number dropped to 21 after its record high of 35, which came in 2001.

Experts say the reason this is happening is because of how much U.S. companies have recovered since the economic downturn and how much global equities have retreated in recent months. In the past, retail, media and computer-related stocks have gained before the gross domestic product grew as investors start to look toward increasing customer demand.