Fascinating! I haven't seen this before!
Nah, most of those guys are relatively small fish from the reddit brigade. From my observations it's likely a small group of unrelated individuals with professional market experience, deep pockets and pretty sophisticated bots. You wanted Wall Street, well they are here and are shaking the market for all it's worth!
This. Trading seemed to start stepping up in ruthlessness / quality around 18 months ago, after the April 13 bump.
...and thanks for your observations, always worth reading.