In particular, the CFTC release notes:
in or about June 2009, Defendants modified a commonly used off-the-shelf trading platform to automatically simultaneously “layer” four to six exceptionally large sell orders into the visible E-mini S&P central limit order book (the Layering Algorithm), with each sell order one price level from the other. As the E-mini S&P futures price moved, the Layering Algorithm allegedly modified the price of the sell orders to ensure that they remained at least three or four price levels from the best asking price; thus, remaining visible to other traders, but staying safely away from the best asking price. Eventually, the vast majority of the Layering Algorithm orders were canceled without resulting in any transactions. According to the Complaint, between April 2010 and April 2015, Defendants utilized the Layering Algorithm on over 400 trading days.
The Complaint alleges that Defendants often cycled the Layering Algorithm on and off several times during a typical trading day to create large imbalances in the E-mini S&P visible order book to affect the prevailing E-mini S&P price. Defendants then allegedly traded in a manner designed to profit from this temporary artificial volatility. According to the Complaint, from April 2010 to present, Defendants have profited over $40 million, in total, from E-mini S&P trading.
As others quickly pointed out, the notion that "layering" is involved in these wild price swings is being studied by multiple agencies. For example: Exclusive: SEC targets 10 firms in high frequency trading probe - SEC document.
The SEC has been seeking evidence of abuse of order types, as well as traditional forms of abusive trading like "layering" or "spoofing" and other issues relating to high-frequency trading that might be violations of the law, SEC Director of Enforcement Andrew Ceresney told Reuters in May (reut.rs/1kwSqF5).
Spoofing and layering are tactics where traders places orders that they cancel before they are executed to create the false impression of demand, aiming to trick others into buying or selling a stock at the artificial price.
I'm pleased that investigators continue to investigate.
On the other hand, even after 5 years the investigators still appear to be uncertain as to exactly what happened and why.
It's disturbing news, all around.