The infrastructure behind every trade.

A demat account holds securities — shares, ETFs, bonds — in electronic form, the same way a bank account holds money. A trading account is what's used to place buy and sell orders on the exchange. The two work together: an order placed through the trading account results in shares moving into or out of the linked demat account on settlement.

Most brokers open both accounts together as a single onboarding process, but they serve distinct legal and functional roles — the demat account is technically maintained via a depository participant, while the trading account is maintained via the broker's exchange membership.

A bank account is the third leg of this setup: funds move between the bank account and the trading account to pay for purchases or receive proceeds from sales, completing the full pipeline from cash to holdings.

In India, electronic securities are held through one of two depositories — NSDL (National Securities Depository Limited) or CDSL (Central Depository Services Limited). A demat account is opened with one of these two, via a depository participant (typically the broker).

The depository is the entity that actually maintains the electronic record of ownership; the broker acting as a depository participant is the interface through which an investor accesses and instructs changes to that record.

Holdings can be transferred between depositories if an investor moves brokers, though the process and any associated charges depend on the specific depository participants and accounts involved.

Settlement is the process of actually exchanging securities for funds after a trade is executed. Indian equity markets moved to a T+1 settlement cycle, meaning a trade executed on a given day (T) is settled — shares credited to the buyer's demat account and funds credited to the seller — on the next trading day.

This is faster than the T+2 or longer cycles used historically and in some other markets, reducing the time capital and securities are tied up in transit between trade execution and final settlement.

Settlement timing affects when bought shares actually become available to sell again or pledge as collateral, and when sold shares' proceeds become available to withdraw or reinvest — a practical detail that matters more for active traders than for buy-and-hold investors.

A depository participant (DP) is the intermediary — typically the broker — authorized to offer demat account services on behalf of NSDL or CDSL. DP charges are a fee levied on each sell transaction from a demat account, separate from brokerage, and are generally fixed per scrip per day rather than based on trade value.

Because DP charges apply per scrip sold rather than per trade value, they disproportionately affect traders who sell small quantities of many different securities compared to those who trade fewer securities in larger size.

DP charges are set largely by the depositories and passed through by brokers, which is why they tend to be relatively similar across brokers compared to brokerage rates, which vary more by broker and plan.

Pledging allows shares held in a demat account to be used as collateral for margin, without selling them — the broker records a pledge against the holding, which then counts toward the margin required for F&O or intraday positions, subject to a haircut (a discount applied to the share's value for margin purposes).

This lets an investor holding a delivery portfolio use it to support trading activity without liquidating the underlying holdings, though the pledged shares remain exposed to the same market risk as before — pledging is a margin mechanism, not a hedge.

If the value of pledged shares falls significantly, the resulting margin shortfall works the same way as any other margin shortfall — it can trigger a margin call or forced position reduction if not addressed.

Nomination lets a demat and trading account holder designate who should receive the account's holdings in the event of the account holder's death, simplifying the transmission process compared to relying solely on a will or legal heirship determination.

Nomination doesn't override a valid will if one exists and is contested, but it does provide a straightforward default path for the depository and broker to follow when transmitting holdings, which is why regulators have periodically required investors to either nominate or explicitly opt out.

Because nomination details (name, relationship, percentage allocation across multiple nominees) are account-level settings, they should be reviewed and updated after major life events rather than left as originally set at account opening.