ExxonMobil is on track to end the week as the most valuable company in America, after earlier being passed by Apple.
Exxon shares are again benefiting from a rise in the price of oil. Exxon now has a market capitalization of $355 billion, compared with Apple's $351.5 billion. Shares of Apple are up 1.5 percent for the week.
Apple first surpassed Exxon on Tuesday afternoon, but settled at No. 2 by the time the stock market closed. On Wednesday it kept the top spot after the close, with a market cap of $337 billion versus Exxon's $331 billion.
Exxon, which had held the top spot since 2005, regained it Thursday, helped by 3.4 percent increase in the price of oil.
Still, many analysts can understand why investors may view Apple as the more valuable company.
Exxon's growth is tied to the price of oil and to the discovery of new oil sources. Apple, meanwhile, is limited only by innovation and ongoing demand for its products. That demand, for now, seems insatiable. Apple also has room to grow, since it commands just a small fraction of the smartphone and personal computer markets.
Exxon shares are still down 10.3 percent since June 30, a time period when oil prices have also dropped 10 percent. Apple shares have gained 13 percent in the same time frame.