Dematerialisation requirement for non promoter holdings enables shift from trade for trade to rolling settlement when connectivity is met. Shift from Trade-for-Trade to Rolling Settlement is permitted where companies have connectivity with both depositories, at least half of non promoter holdings are dematerialised certified by the RTA or, if no RTA, by a practicing Company Secretary or Chartered Accountant, and there are no other grounds for continuing Trade-for-Trade; stock exchanges must report actions taken in their development reports.