Just 10 years ago, finance was a small-data discipline. The small-data approach was partly due to the actual lack of data. To most investors, exchanges offered only four prices per stock per day: Open, High, Low and Close, and all of those were reported the following day (on the T+1 basis). Even the largest market makers did not store intraday data beyond what was mandated by regulators. Commodity trading floors, for instance, had only 21 days of history on hand until approximately five years ago. Finance Ph.D. programs almost exclusively taught analysis of closing prices, mentioning intraday variations only in passing. Today, real-time streaming dataRead More →

By Irene Aldridge Just over two weeks ago, NASDAQ stopped trading midday, fueling a new wave of speculation about the reliability and, ultimately, appropriateness of using computer technology in trading. Critics of trading algorithms readily jumped on the news bandwagon, happily denouncing technology as a source of all economic ills. In reality, however, on Aug. 22, 2013, NASDAQ halted its servers to comply with instructions from the U.S Securities and Exchange Commission (SEC). Had NASDAQ continued trading as usual that day, it would undoubtedly face hefty fines on the order of $10 to $15 million, like the penalty assessed to the New York Stock ExchangeRead More →