I suspect dividend counters like CMA are treated by the investing community as 'fixed deposit instruments', whereby holders of these counters are all yield-seekers, and they do not buy and sell frequently. They just buy the units and hold them tightly to their chest, awaiting the quarterly dividend payouts. Hence, the reason for the shallow trading.
It is rightly so that a counter like CMA should stay stable and resilient for such investors, being there to offer income to her unit-holders. If the fundamentals of a counter like CMA changes, it is more detrimental than another counter (not a yield counter) whose fundamentals changes. The reason being when a counter with such shallow trading changes for the worse, there is not enough time for a unitholder 'to pull out' before the price goes into a freefall downwards.
Why do you say this counter is volatile ?
CMA Price at posting:
$2.13 Sentiment: Buy Disclosure: Held