Income tax disllow

sir,

we are filed return  Share Speculation Loss C/f   from 2014   all return filed in within period  but  AY 2018-19 filling return  Disallow loss u/s 139-143(1) a (iii)    [ speculation loss c/f only 4 year]  [not c/f 8 year !!!!]    only business speculation loss c/f 8 year 

please explain  loss  rule  [business  or share speculation (2, 3 trade only)  ]    or capital gain or  speculation  in business in daily basisi]