An trading and demat account is most required for purchasing and selling and holding shares. However the trading and demat account could become dormant if there are sustained periods of inactivity. And no trade can be made through an dormant trading account until the reactivation process is completed. Read here to know more.
An individual may choose to convert their physical mutual fund units held through statement of account (SOA) mode to dematerialise mode online. However the online method is only applicable for National Securities Depository Limited (NSDL) demat account holders. For Central Depository Services Limited the conversion process is presently offline.
A share which was once actively traded on stock exchanges could turn illiquid one day due to multiple reasons like trading suspension/block or any news event, etc. Further an investor cannot exit from such stocks by selling them on the stock exchange since there is no buyer.