There's no such thing as a global trademark per se, but if you were to register a trademark in every country in the world, the total price would come up to thousands of US dollars.
This may sound discouraging, but please remember that businesses usually don't have to be concerned about trademark infringement in countries where they're not operating. Instead, a typical strategy includes getting a trademark in countries where the brand is currently active, plus countries where it plans to expand to shortly. You can learn more about the optimal trademark strategy in this article.
If you're considering registering a trademark in multiple countries, you may be interested in our international packages.