Microsoft's market cap hit $2.89 trillion as it overtook Apple as the world's most valuable public company

• Microsoft's market cap hit $2.89 trillion on Friday as it knocked Apple off the top spot.
• The company's investment in AI has boosted its share price value this year.
• Meanwhile, slower iPhone sales in China have made life trickier for Apple.

Microsoft closed out Friday as the world's most valuable publicly traded company, pushing its long-time rival Apple off the top spot.