I really don't know if we can call trading volume a good indicator though. There are a lot of exchanges doing wash trading and also some are doing OTC ~
That's what I thought too while reading the article. Also, I think that most new investors are not traders and thus they are not contributing to the trading volume.
I wonder if it is possible at all to estimate the influx of new investors? The rising of the price would be a clear evidence of that, but what else can tell us that the number of Bitcoin adopters is increasing? Properly organized polls? Maybe. But what else?
Anyway, it is clear that this
... lesser investors were seen penetrating into the digital currency market. The lower trading volumes registered between June to October last year was clear evidence.
is a flawed argument.