Dematerialisation requirement enables shift from trade-for-trade to rolling settlement when majority holdings are in demat form. Shifting securities from Trade for Trade Settlement to normal Rolling Settlement is conditioned on companies having established connectivity with both depositories and on at least 50% of other than promoter holdings being dematerialised, certified by the Registrar and Transfer Agent or, if none, by a practicing company secretary or chartered accountant; exchanges must ensure no other grounds for TFTS continuation and report actions to SEBI.