Dematerialization (securities) in the context of "Brokerage firm"

A security is a tradable financial asset. The term commonly refers to any form of financial instrument, but its legal definition varies by jurisdiction. In some countries and languages people commonly use the term "security" to refer to any form of financial instrument, even though the underlying legal and regulatory regime may not have such a broad definition. In some jurisdictions the term specifically excludes financial instruments other than equity and fixed income instruments. In some jurisdictions it includes some instruments that are close to equities and fixed income, e.g., equity warrants.

Securities may be represented by a certificate or, more typically, they may be "non-certificated", that is in electronic (dematerialized) or "book entry only" form. Certificates may be bearer, meaning they entitle the holder to rights under the security merely by holding the security, or registered, meaning they entitle the holder to rights only if they appear on a security register maintained by the issuer or an intermediary. They include shares of corporate capital stock or mutual funds, bonds issued by corporations or governmental agencies, stock options or other options, limited partnership units, and various other formal investment instruments that are negotiable and fungible.

Book entry is a system of tracking ownership of securities where no certificate is given to investors. Several terms are often used interchangeably with "book entry" shares including "paperless shares", "electronic shares", "digital shares", "digital stock certificates", and "uncertificated shares". Some of these terms have somewhat different connotations but, at least in the United States, state securities laws only recognize certificated and uncertificated shares. In the case of book-entry-only (BEO) issues, while investors do not receive certificates, a custodian holds one or more global certificates. Dematerialized securities, in contrast, are ones in which no certificates exist; instead, the security issuer, its agent or a central securities depository keeps records, usually electronically of who holds outstanding securities.

Most investors who use an online broker or even a regular full-service broker will have their shares held in book-entry form. This is generally convenient, as one does not have to preserve physical stock certificates, and can buy/sell securities without turning certificates in or having new ones issued. Also, replacement costs for certificates are high in case one loses them, while book-entry ownership can never be lost thanks to technological backups.

A central securities depository (CSD) is a specialized financial market infrastructure organization holding securities such as shares or bonds, either in certificated or uncertificated (dematerialized) form, allowing ownership to be easily transferred through a book entry rather than by a transfer of physical certificates. This allows brokers and financial companies to hold their securities at one location where they can be available for clearing and settlement. In recent decades this has usually been done electronically, making it much faster and easier than was traditionally the case where physical certificates had to be exchanged after a trade had been completed.

In some cases these organizations also carry out centralized comparison and transaction processing such as clearing and settlement of securities transfers, securities pledges, and securities freezes.