US senators pressing for the US government to regulate high-speed computerised trading were given more ammunition yesterday. Trading on Wall St went haywire yesterday afternoon, when the S&P 500 index fell by nearly 8.6% in five minutes, according to a report in the FT.The market relies heavily on computerised trading systems, known as “algos”. Traders believe a dealer may have mistyped ‘billions’ for ‘millions’ but were left wondering why the sophisticated platforms used for trading failed to pick up the error. US senators, let by Ted Kaufman, the democratic senator from Delaware, now plan to press for sweeping reforms to the way financial institutions use algorithmic trading with renewed vigor. Any such move will have implications for the high-speed trading systems used in Europe by the London Stock Exchange, BATS, and Chi-X. Read more here.