From the creator of Citadel's HFT desk for options: "You have multiple HFT trading firms and sometimes their agendas are complementary and sometimes they’re not. There could be a time where these HFT programs unintentionally collaborate and you have a two- or three-minute period where the markets are going crazy. Then other traders respond to it and it simply gets out of control."
GATA today urged the U.S. Securities and Exchange Commission and the U.S. Commodity Futures Trading Commission to investigate the Goldman Sachs Group Inc. computer trading program that, according to a federal prosecutor, the bank acknowledges can be used to manipulate markets.
The ETF bubble looks like it may be the next one to burst. WSJ just out that the CFTC is probing the USO ETF for price moves coinciding with trades in and out of crude-oil contracts. The USO has recently gotten prominent media attention over allegations that it is a perpetually value bleeding asset, and potentially a pyramid structure.