What is the rarest sloth?

As a cryptocurrency and finance professional, I find myself often delving into unique topics beyond my primary field. But this question about the rarest sloth intrigues me. So, if I may pose the inquiry in a simulated questioner's tone: "Among the diverse species of sloths, which one stands out as the rarest? Is it the enigmatic pygmy three-toed sloth, found only in the dense forests of Central America? Or perhaps it's the brown-throated three-toed sloth, whose habitat is increasingly threatened by deforestation? Could it be a newly discovered subspecies, hidden away in some remote corner of the rainforest? The mystery of which sloth is truly the rarest begs to be solved.