I noticed a very distinctive saw-tooth profile on the red line on 5.Accounts-Transacting. At first, I thought, haha bots rule the STEEM, but then I noticed it's actually HIVE (oops) and at first it looked correlated to weekends, but after checking a few dates, the peak hits saturdays, sundays, mondays.. Then I noticed similar shapes on 4th and 6th grapsh as well.
It it just a normal activity based around having-more-time-on-weekends and post curation timeouts? But if it were this, I'd expect similar thing on STEEM as well, and apparently it's not there.