What is the value of mantle?

Excuse me, I'm quite perplexed about the term 'mantle'. Could you possibly clarify what exactly is the value of mantle in the context of cryptocurrency and finance? I've heard it mentioned in several discussions but haven't quite grasped its significance. Is it a specific token, a technological aspect, or perhaps a term related to a certain investment strategy? I'd appreciate it if you could elaborate on its meaning and the potential impact it might have in the industry. Thank you for your time and assistance in this matter.