Here are some of the world's top billion-dollar companies (also called "unicorns" if privately held, or just mega-cap companies if public), based on market capitalization as of 2025:

Top Public Companies (Trillion-Dollar Range)

These are some of the largest in the world:

1. Apple (AAPL) – Over $2.7 trillion

2. Microsoft (MSFT) – Over $3 trillion

3. Saudi Aramco – Around $2 trillion (varies with oil prices)

4. Alphabet (GOOGL) – Over $1.8 trillion

5. Amazon (AMZN) – Around $1.7 trillion

6. Nvidia (NVDA) – Surpassing $2 trillion in early 2025

7. Meta (META) – Around $1.3 trillion

8. Berkshire Hathaway – Over $850 billion

Top Private Billion-Dollar Companies (Unicorns)

These companies are not yet public but have private valuations over $1 billion:

ByteDance (TikTok owner) – ~$250 billion

SpaceX – ~$180 billion

OpenAI – Estimated at $80–100 billion

Stripe – ~$50 billion

Shein – ~$60 billion

If you’re looking for a list by industry (tech, oil, automotive, etc.) or want to know which company leads in a specific count

ry, I can provide that too. Just let me know!