Dematerialisation requirement enables shift from trade-for-trade to rolling settlement when non-promoter holdings are dematerialised and certified. Shifting securities from Trade-for-Trade Settlement to Rolling Settlement is permitted where companies have connectivity with both depositories and where at least half of the non-promoter shareholding is dematerialised, as certified by the Registrar and Transfer Agent or, if no separate RTA exists, by a practising company secretary or chartered accountant; exchanges must also ensure no other grounds for continuation of TFTS and report actions in their development reports.