San Francisco:The four tech giants are worth nearly $5 trillion in combined market capitalisation, with Apple stock and Amazon stock both over $1.5 trillion.
Analysts and market watchers would keep an eye on figures and trends in e-commerce, streaming, advertising, search, app stores, social media and cloud computing.
Facebook rescheduled its second-quarter(Q2) results from Wednesday to Thursday(29 July to 30 July) owing to the conflict as Zuckerberg was to testify before the House Judiciary Committee and the Antitrust Subcommittee.
The shares of all Big Four tech giants slightly rose after the Congressional hearing as the market opened.
Amid intense grilling on issues that centred on market power derived from the uninhibited collection and access to data, all four CEOs focused their attention on the value of their innovations and services to consumers. They testified via video link to lawmakers in Washington DC.