Bill Ackman's investment strategy

What happened: Bill Ackman, founder of Pershing Square Capital Management, has taken significant stakes in tech giants Microsoft and Amazon. Microsoft's stock surged 25% in just four days following its earnings report on July 29. Ackman's company believes Amazon's retail business can nearly double in size, driven by its cloud services, AWS.

Market impact: Ackman's investments have driven interest in these tech stocks. Microsoft's recent rally has pushed its market cap above $2.1 trillion, while Amazon remains the world's largest company by sales. Ackman's focus on fundamentals and qualitative analysis may influence other investors' decisions, impacting these tech stocks and potentially the broader sector.

What to watch next: Microsoft's next earnings report, scheduled for October 25, will provide insights into its growth trajectory. Amazon's Prime Day in Q4 will be a key catalyst for its retail business. Additionally, watch for any regulatory developments around big tech, which could impact both companies.