I don't think there's anything strange happening, and neither do I think that there are manipulatory forces at play.

The market exploded towards the end of 2017, and that growth exploded even further once media outlets started talking about it. Transaction confirmations then grinded to a crawl with transaction fees skyrocketing. The growth stopped, and people stopped talking about it. Bitcoin is still in a very good place value-wise considering how just a few months ago, people were wondering if it was possible for Bitcoin to reach $10k by the year's end, and that prediction was completely shattered. It's in a far better place than it could be in my opinion.

Either way, maybe this is a good thing. The network can't handle the demand as it is, and things may need to settle down at least until the Lightning Network is ready.