Google Trends and data on wallet sizes. Very little retail interest so far - it's mainly big holders who have accumulated.
Even when BTC broke $10k we saw little mainstream media interest. In 2017 the BBC and just about every other major news site ran daily articles on crypto. Almost nothing this time. I guess they still feel burned by last time.
It's starting to change, but only just getting going now.
You dont want retail interest at this part of the cycle. We should still be in accumulation phase. If we start to see meaningful distribution that would be concerning.