I think bots and node instability are the only possible explanation for that pattern. I'm not aware of any node instability (but I have not been following). Bots are the more likely explanation IMO.

More manipulation? More bots trying things at certain moments but not at others?

I always wonder about steem, it has no real dapps there.

Which is sad. Such a great potential Justin seems to be squandering ...

As long hive will work out, i have no problem with it :)