Good catch. I think it's because the market is a cyclical phenomenon. At the end of the day the market is just a big number of actors taking decisions influenced by each other. This hivemind creates certain patterns. At the end of the day, the graph is showing solid growth, and bitcoin recovers always at a higher price after the bubbles crash. This means non holders are getting increasingly nervous trying to wait for a perfect price and get in as soon as the ongoing bubble crashes. As the ongoing bubbles don't crash as as hard, the holders don't panic sell as hard it's also deductible. In other words the asset is getting stronger with time. Everyone knows bitcoin is the most exciting thing to hold long term on earth.