I’ve been looking around trying to find a disclosure of how the trends are calculated, but it seems pretty obscure. 1M tweets on Bitcoin may be a lot, or not as much as one might figure.
Ideally, the figure would be relativized against other tweets, to get a relative comparable number (a bit like what we see here: https://trends24.in/), and we’ll also have a timeframe (i.e. the 1M is in what period of time).  Without at least some information that allows us to comprehend the variable, the number of Tweets in the trend is not easy to interpret on its own, as it lacks the context for its comprehension.

Another possibility is to see the evolution of the number over period of time (i.e. daily). That would allow us to see how the number evolves over time to some degree.