No, no, no. The reason the price moved is because market makers saw the trades on one exchange, then updated their quotes on others. This is normal, regular, to-be-expected, good behaviours. Calling it front running just shows a lack of basic understanding. Or in Brad/Lewis case, probably an ulterior motive (selling Thor or promoting IEX).
In fact, the book even shows it's not front running because Thor just delays orders so they hit all market makers simultaneously, so they cannot react.
There's no "market", but a group of exchanges. The orders to a single exchange execute immediately; there's no way to do what you're saying. And across exchanges, this behavior is exactly like it should be. Here's how to verify: increase the times.
Suppose the trader moving a big block sent an order to one market to buy up 10K shares. Then he sits for an hour. In that scenario, do we expect the price to stay the same? Of course not! Everyone sees the one order on that one market and reacts (canceling their outstanding quotes on other markets, for instance). That's all that's going on, except faster than humans can react. Why is it suddenly bad when a computer does it?
Front running is well defined. Front running is not just acting like a normal intelligent person and updating your quotes (or even trading) after a large order executes.
In fact, the book even shows it's not front running because Thor just delays orders so they hit all market makers simultaneously, so they cannot react.
There's no "market", but a group of exchanges. The orders to a single exchange execute immediately; there's no way to do what you're saying. And across exchanges, this behavior is exactly like it should be. Here's how to verify: increase the times.
Suppose the trader moving a big block sent an order to one market to buy up 10K shares. Then he sits for an hour. In that scenario, do we expect the price to stay the same? Of course not! Everyone sees the one order on that one market and reacts (canceling their outstanding quotes on other markets, for instance). That's all that's going on, except faster than humans can react. Why is it suddenly bad when a computer does it?
Front running is well defined. Front running is not just acting like a normal intelligent person and updating your quotes (or even trading) after a large order executes.