Shares of Apple and Microsoft have taken opposite roads in 2013.
Apple's precarious position stems from a combination of factors. The S&P 500 is a weighted index --?that is, certain companies are given more power over the movement of the index than others --?and weights are based broadly on each company's market capitalization.
By virtue of its impressive market cap, Apple enjoys the highest weighting in the index, at about three percent. This means little when the stock is up, but magnifies the effects of a downturn like Apple has faced this year, having slumped by around one percent year-to-date.
Microsoft sports the third-highest weight in the index?with just under two percent. Combined with the company's nearly 40 percent year-to-date share price leap and second place ExxonMobil's lackluster performance, this means it is Microsoft, rather than Apple, that is the tech company most likely to lead the S&P when trading closes on Dec. 31.
According to data compiled earlier this week by Bloomberg, Apple is not only in danger of losing its leadership position, but may even end the year as the biggest drag on the index. At the close of trading Monday, Apple's 13.74-point slump was good enough for a corresponding 1.6-index point decline for the S&P, compared to a 9.2-index point boost from Microsoft.