national grid plc ng shares inched down 068 to £1019 tuesday on what proved to be an allaround rough trading session for the stock market with the ftse 100 index ukx falling 061 to 752139 national grid plc closed £252 short of its 52week high £1271 which the company reached on may 18 trading volume 39 m remained 53 million below its 50day average volume of 92 m editors note this story was autogenerated by automated insights an automation technology provider using data from dow jones and factset see our market data terms of use