Yes they are. It is always same thing happening after price drops. Whales will start accumulating slowly until they cause next big explosion to make people buy in around expensive prices.
Do you think they are accumulating Bitcoin Cash?
Who in their right mind would want to accumulate that? It's purely speculative asset with no long term value.
I've been watching Mysterium price charts lately and it looks like whale accumulation period during the past few days. Downtred suddenly stopped and reverted, trading volume increased, with a few big volume spikes. Still they try to keep the price relatively low. And all this just a few days before monthly development news are expected to be published.
That looks more like an accumulation IMHO.