What is an all time low in Coinmarketcap?

Could you elaborate on the concept of an 'all-time low' in the context of Coinmarketcap? As a cryptocurrency enthusiast, I'm particularly interested in understanding how this metric is determined and what it signifies for the market. Specifically, I'm wondering if an all-time low indicates a buying opportunity, a sign of market distress, or perhaps a turning point in the crypto landscape. Your insights would be invaluable in helping me navigate the volatile yet exciting world of digital currencies.