As of October 2021, the top 10 gambling companies with the highest market capitalization are:
1. Flutter Entertainment
2. Evolution Gaming
3. Las Vegas Sands
4. MGM Resorts International
5. Wynn Resorts
6. International Game Technology (IGT)
7. Aristocrat Leisure
8. Galaxy Entertainment Group
9. GVC Holdings
10. Caesars Entertainment
Please note that the market capitalizations of these companies may vary over time due to market fluctuations. It is always advisable to check the latest financial data for accurate rankings.