11.5 Market Participants

Key Takeaways

  • A broker acts as agent for a commission; a dealer acts as principal for a markup or markdown, and no single trade carries both.
  • Market makers must post continuous two-sided quotes and honor them up to displayed size, earning the spread.
  • FINRA registers, examines, and enforces; the MSRB writes municipal rules but does not enforce them.
  • Transfer agents keep ownership records while custodians safeguard assets and process income and corporate actions.
  • DTCC subsidiaries DTC, NSCC, and FICC provide depository and clearing services, with netting reducing settlements.
Last updated: June 2026

Broker-Dealers: Agent vs. Principal

A broker-dealer is a firm in the business of buying and selling securities. The capacity in which it acts on a given trade controls its compensation and its risk.

CapacityRoleCompensationMarket risk
Broker (agent)Arranges a trade for a customerCommissionNone
Dealer (principal)Trades from its own inventoryMarkup/markdownBears it

Most firms do both, hence "broker-dealer." A bedrock Series 7 rule: a firm cannot charge both a commission and a markup on the same transaction—it is one capacity per trade. When a firm sells from inventory it adds a markup; when it buys into inventory it takes a markdown.

Registration requirements: file Form BD with the SEC, join an SRO (FINRA), register in each state of business ("blue-sky"), and register associated persons.

Market Makers

Market makers supply liquidity by continuously quoting both a bid and an offer.

ObligationDetail
Continuous two-sided quotesAlways a bid and an ask
Honor quotesTrade at posted prices up to displayed size
Minimum sizeGenerally 100 shares for equities

Market makers earn the spread—buy at the bid, sell at the ask. They are not required to guarantee investors a profit; investors can still lose. Tighter spreads signal more competition and deeper liquidity.

Self-Regulatory Organizations

SROs are non-governmental bodies that write and enforce rules for members under SEC oversight.

FINRA (Financial Industry Regulatory Authority) is the primary broker-dealer SRO:

FunctionDescription
RegistrationLicenses firms and individuals
Qualification examsAdministers the Series 7 (125 scored + 5 pretest questions, 225 minutes, 72% to pass, $395 fee)
RulemakingConduct rules for members
EnforcementInvestigates and disciplines

The MSRB (Municipal Securities Rulemaking Board) writes rules for municipal dealers and advisors and operates EMMA, but it does not enforce its own rules—enforcement falls to FINRA (for broker-dealers) and bank regulators or the SEC. Exchanges such as the NYSE, NASDAQ, and the Cboe also act as SROs.

Transfer Agents and Custodians

Transfer agents keep the official ownership records for an issuer: they process transfers, issue and cancel certificates, distribute dividends, and handle corporate actions such as splits and mergers. They are regulated by the SEC.

Custodians safeguard customer securities and cash. Their duties include settlement (receive/deliver), income collection (dividends and interest), processing corporate actions, and reporting to beneficial owners. Bank custodians serve institutions; broker-dealers custody retail accounts. The exam trap: the transfer agent keeps the record of who owns the shares, while the custodian holds the assets.

Clearing Corporations

Under the DTCC holding company:

SubsidiaryFunction
DTCSecurities depository; book-entry ownership
NSCCEquity and corporate bond clearing; central counterparty
FICCGovernment and mortgage-backed securities clearing

Netting dramatically reduces settlement volume. Example: Firm A owes Firm B 1,000 shares while Firm B owes Firm A 800 shares. Without netting, two deliveries occur (1,000 and 800). With NSCC netting, Firm A delivers a net 200 shares to Firm B—one obligation instead of two.

Investment Advisers

An investment adviser gives securities advice for compensation, governed by the Investment Advisers Act of 1940.

FeatureInvestment adviserBroker-dealer
StandardFiduciaryRegulation Best Interest (Reg BI)
PayFees, often a percentage of AUMCommissions/markups
RegistrationSEC if AUM > $100 million, otherwise stateSEC + FINRA
Core activityAdviceTransactions

The fiduciary standard requires the adviser to place the client's interest first; broker-dealers operate under Reg BI, a best-interest standard at the time of a recommendation.

SIPC and Customer Protection

The Securities Investor Protection Corporation (SIPC) protects customers if a member broker-dealer fails. It covers up to $500,000 per separate customer, of which a maximum of $250,000 may be cash. SIPC restores missing securities and cash, not market losses—it does not insure against a decline in a security's value. Membership is mandatory for nearly all registered broker-dealers, and "SIPC member" status must be disclosed.

Clearing vs. Introducing Firms

Broker-dealers split into two operational roles the Series 7 tests:

Firm typeRole
Introducing (correspondent) firmHandles the customer relationship and orders; does not hold customer assets
Clearing (carrying) firmHolds customer cash/securities, clears and settles, sends confirmations and statements

This division is documented in a clearing agreement, and customers must be told which firm carries their account.

Common Exam Traps

  • Agent = commission, no risk; principal = markup/markdown, bears risk. A firm cannot charge both on the same trade.
  • Market makers must post two-sided quotes and honor them up to size; they never guarantee investor profit.
  • FINRA enforces; the MSRB only writes rules and runs EMMA—the MSRB has no enforcement power.
  • Transfer agent = ownership records; custodian = safekeeping of assets. Do not merge these roles.
  • SIPC covers $500,000 total / $250,000 cash per customer for a failed broker-dealer, not market losses.
  • An investment adviser owes a fiduciary duty; a broker-dealer owes Reg BI, a recommendation-time best-interest standard.
Test Your Knowledge

A broker-dealer fills a customer's buy order by selling shares out of its own inventory. In this trade the firm acts as a:

A
B
C
D
Test Your Knowledge

Which statement about the MSRB is correct?

A
B
C
D
Test Your Knowledge

Which entity maintains the official record of who owns an issuer's shares and processes ownership transfers?

A
B
C
D