The program placed orders in 25-millisecond bursts involving about 500 stocks, according to Nanex, a market data firm. The algorithm never executed a single trade, and it abruptly ended at about 10:30 a.m. ET Friday.
via Mysterious Algorithm Was 4% of Trading Activity Last Week – CNBC.com – US Business News – CNBC.
Translation: The ultimate goal of many of these programs is to gum up the system so it slows down the quote feed to others and allows the computer traders (with their co-located servers at the exchanges) to gain a money-making arbitrage opportunity.
HFT affects all investors to an extent, because stocks are now priced differently than in the past. The market used to consist mostly of investors analyzing cash flows and balance sheets, trying to calculate a company’s fair value. HFTs, on the other hand, react to movements in stock prices alone. That is not necessarily a bad thing, but since HFTs are responsible for two-thirds of the trading volume, we have the strange situation where they can set the price based on what they perceive others’ perceptions to be.
via This is What Wall Street’s Terrifying Robot Invasion Looks Like | Motherboard.