Antonyms for the word "under-valuing" would be "over-valuing" or "appreciating". When people undervalue something, they fail to acknowledge its true worth or potential. Conversely, when someone overvalues something, they exaggerate its value, usually leading to unrealistic expectations. Appreciating something involves recognizing and valuing its worth, whether it is a person, object, or concept. Appreciation leads to gratefulness and admiration for the value that something brings to the world. It is important to be aware of our tendencies towards under-valuing or over-valuing, and strive to approach things with an open mind and fair assessment of their worth.