what are the big 4 companies

The "Big 4" companies refer to the four largest global accounting and professional services firms. They are:

1. Deloitte LLP (Deloitte)
2. PricewaterhouseCoopers (PwC)
3. Ernst & Young (EY)
4. Klynveld Peat Marwick Goerdeler (KPMG)

These firms dominate the accounting, auditing, tax, consulting, and advisory markets worldwide. Their combined revenue in 2024 was approximately $212 billion, with Deloitte being the largest at about $67.2 billion in revenue. They employ hundreds of thousands of professionals globally and serve many of the largest corporations and governments.