Apple not going down easy as it overtakes Google parent Alphabet

Apple's (AAPL) stock is trying to shake the No. 2 stigma. It's not going down without a fight.

Just one day after being passed up by Google's parent Alphabet (GOOGL) as the world's most valuable company, Apple Wednesday retook the top perch with a market value of $534.2 billion. Shares of Apple rose Wednesday $1.87, or 2%, to close at $96.35.

That was enough to edge out Alphabet, since shares of the online advertising company Wednesday closed down $37.70, or 5%, to $726.95. That gives Alphabet a market value of $515.1 billion, or 3.6% less than Apple. Alphabet is now the No. 2 most valuable stock ahead of Microsoft (MSFT) at $412.5 billion and Exxon Mobil (XOM) at $326.7.

Alphabet clearly has the momentum, though. Shares of Alphabet are up 46% over the past 12 months while shares of Apple are down 20%.

Investors should expect lots of back and forth between Alphabet and Apple - as the two companies' valuations are so close. Besides, it's typical for companies to bounce around from the top perch. Energy giant Exxon Mobil lost the most valuable notch to Microsoft in 1997 - but retook it in 2004 - only to lose it again to Apple in 2012.

Staying on top is tough - especially in technology - where new developments can shake the balance of power overnight.

MOST VALUABLE COMPANIES IN S&P; 500

Company, symbol, Market value ($ billions)

Apple, AAPL, $534.2

Alphabet, GOOGL, $515.1

Microsoft, MSFT, $412.5

Exxon Mobil, XOM, $326.7

Facebook, FB, $320.7

Sources: S&P; Capital IQ, USA TODAY