and make decisions in a way we havent been able to ever before, said Gary King, a social science professor at Harvard University and a co-founder of Crimson Hexagon, a data analysis firm based in Boston.The Obama campaign employs rows of people manning computers that monitor Twitter sentiment about the candidates in key states. Google scientists are working with the Centers for Disease Control and Prevention to track the spread of flu around the world by analyzing what people are typing in to search. And the United Nations is measuring inflation through computers that analyze the price of bread advertised in online supermarkets across Latin America.Many questions about big data remain unanswered. Concerns are being raised about personal privacy and how consumers can ensure that their information is being used fairly. Some worry that savvy technologists could use Twitter or Google to create false trends and manipulate markets.Even so, sociologists, software engineers, economists, policy analysts and others in nearly every field are jumping into the fray. And nowhere has big data been as transformative as it has been in finance.Wall Street is all about information advantage. Every little bit could mean the difference between a bonanza or a devastating loss, and so big data is being fed into computers to power high-frequency trading algorithms and directly to traders in every way imaginable.Hedge funds are experimenting with scanning comments on Amazon product pages to try to predict sales. Banks are tallying job listings on Monster as an indicator of hiring. Investment firms are conducting computer analyses of the financial statements of public companies to search for signs of a bankruptcy.Why wait for the government to release official numbers on auto sales, home sales and retail sales when the trends could be gleaned weeks or even months earlier by analyzing publicly available data online?Five years ago, only 2 percent of investment firms were incorporating Twitter analysis and other forms of unstructured data into their trading decisions, according to a report by Adam Honore, a research director at Aite, a financial services consulting group based in Boston. By 2010, the share of companies experimenting with this technology jumped to 35 percent. Today, Honore said, that number is closer to 50 percent.Big data is fundamentally changing how we trade, Honore said.Data in motionRichard Tibbetts, chief technology officer at StreamBase, a Lexington, Mass., company that provides tools for analyzing large amounts of data, calls it examining data in motion. The trick is to be able to find the digital smoke signals amid all the other stuff. Traders who were analyzing Twitter for unusual activity, for instance, were able to get the news of Osama bin Ladens death and a massacre in Norway hours before the information was officially confirmed, giving them a significant jump on their colleagues who learned of the events through traditional news sources.The new generation of trader expects to have dozens of tools at their fingertips instead of just a Bloomberg terminal, Tibbetts said.Hawtin began experimenting with trading on a social-media sentiment algorithm in the spring of 2011, tapping $40 million from his now-closed