Check out the history of trades. Has anyone seen anything like...

Check out the history of trades. Has anyone seen anything like this? I know about bot trades etc, but 95% of todays trades have been bots, and look at the last half hour. All bots.

The only conclusion i can come up with is that the algorithm is dodgy or that for some unknown reason it continuosly sells/buys based on index movements. Can someone explain? Is ths part of a manipulation? And what about the brokerage costs incurred?