The Dominance of Big Four Firms in Tech Auditing

In today's tech-driven era, Apple, Microsoft, Alphabet, Amazon, Nvidia, Meta, and Tesla, collectively referred to as the Magnificent Seven, command an extraordinary market value exceeding $20 trillion.

Responsible for auditing these tech titans are four globally recognized auditing giants: PwC, Deloitte, EY, and KPMG, known collectively as the Big Four.

These accounting leaders play a crucial role in analyzing and verifying the financial integrity of the world’s leading tech firms. Their audits are vital for maintaining openness and answering to investors, regulators such as the SEC, and other interested parties.

Microsoft's Financial Scrutiny

Deloitte is tasked with overseeing Microsoft's finances. Per policies, Microsoft’s auditor selection is ratified yearly by stakeholders. The SEC mandates that audit partners rotate at least every five years. Having audited Microsoft since 1986, Deloitte's services cost Microsoft $78.4 million in the fiscal year ending June 30, 2025.

As of year-end 2025, Microsoft's market value stands at $3.61 trillion, marking a 15% year-to-date increase in stock value.

Apple

Apple has engaged EY as its auditor since 2009. The technology leader allocated $30 million to EY for the fiscal year concluded on September 27, 2025.

Apple's market capitalization is close to $4 trillion with a stock increase of 9% so far this year.

Alphabet’s Auditors

EY handles the audit responsibilities for Alphabet, the umbrella company of Google. During 2024, Alphabet's expenditure for EY's services amounted to $6.5 million, down from $41 million the previous year.

As of the latest valuation, Alphabet, led by Sundar Pichai, stands at $3.7 trillion, with a stock rise of 62% year-to-date.

Amazon’s Audit Partnership

Amazon benefits from EY's auditing since 1996. In 2024 alone, Amazon invested $51 million into EY’s audit services.

Approaching the end of 2025, Amazon is valued at $2.43 trillion, yet its stock has fallen behind its peers over the past five years.

Nvidia’s Oversight

PwC takes charge of auditing Nvidia for its fiscal year concluding on January 31, 2026. PwC has continually audited Nvidia since 2004.

The chipmaker, a leader in AI, reached a historical valuation milestone of $4 trillion in 2025. Nvidia's audit-related expenditure for PwC's services was $10 million in 2025.

Meta's Audit Procedures

Handling Meta’s audit is EY, which has maintained this role since 2007. For the fiscal year concluding December 31, 2025, Meta approved EY as its public auditing firm.

Meta reported $36.3 million in audit fees in 2024. The company's valuation is $1.66 trillion, with a stock increase of 12.5% year-to-date.

Tesla's Financial Review

Tesla has entrusted PwC with its auditing responsibilities since 2005. The company has faced a challenging year due to controversies surrounding Elon Musk's political involvements.

Despite a hard start to the year that halved its share value, Tesla’s stock has rebounded, closing 2025 with a 19% gain, valued at $1.6 trillion.