Lesson 510 min

Market Participants

Learn who trades in the stock market and the different roles participants play.

Learning Objectives

  • Distinguish between retail and institutional investors
  • Understand what market makers do and why they matter
  • Learn about the role of brokers
  • Recognize how different participants influence the market

Market Participants#

The stock market isn't just one monolithic entity—it's a complex ecosystem of different participants, each playing a specific role. Understanding who these players are helps you see where you fit in and how the market actually functions.

The stock market brings together various participants: individual investors like you, large institutions, market makers who provide liquidity, and brokers who facilitate trades.

Retail Investors#

Retail investors are individual, non-professional investors who buy and sell securities for their personal accounts. That's you!

Characteristics of Retail Investors#

  • Trade for personal investment goals (retirement, wealth building)
  • Generally trade smaller amounts compared to institutions
  • Use brokerage accounts to access the market
  • Make decisions independently or with financial advisors

Retail Investor Growth#

The retail investor landscape has changed dramatically:

EraCharacteristics
Pre-2000sHigh commissions, limited access, broker-dependent
2000s-2010sOnline brokers emerge, lower commissions
2020sCommission-free trading, mobile apps, increased participation

Today's retail investors have more tools, information, and low-cost options than ever before. You can access the same markets as professional investors, though institutions still have some advantages in resources and information processing.

Institutional Investors#

Institutional investors are organizations that invest large sums of money on behalf of others. They're the "big players" in the market.

Types of Institutional Investors#

TypeDescriptionExample
Mutual FundsPool money from many investors to buy diversified portfoliosVanguard Total Stock Market Fund
Pension FundsManage retirement savings for employeesCalPERS, Teachers' Retirement System
Hedge FundsUse sophisticated strategies for accredited investorsBridgewater Associates, Citadel
Insurance CompaniesInvest premiums to meet future claimsMetLife, Prudential
EndowmentsManage funds for universities and nonprofitsHarvard Endowment, Yale Endowment
ETF ProvidersCreate exchange-traded funds tracking indicesBlackRock (iShares), State Street (SPDR)

Why Institutional Investors Matter#

  • Move markets: Their large trades can significantly impact stock prices
  • Own most stocks: Institutions own roughly 70-80% of the U.S. stock market
  • Set standards: Their buying patterns can influence which companies succeed
  • Provide liquidity: Their trading activity helps keep markets functioning

Institutional vs. Retail

While institutional investors have more resources, retail investors have advantages too: flexibility, no pressure to meet quarterly targets, and the ability to hold investments indefinitely without reporting requirements.

Market Makers#

Market makers are firms that stand ready to buy and sell stocks at publicly quoted prices, providing liquidity to the market.

How Market Makers Work#

  1. Quote bid and ask prices continuously throughout the trading day
  2. Buy from sellers even when there's no immediate buyer
  3. Sell to buyers even when there's no immediate seller
  4. Profit from the spread between bid and ask prices
  5. Manage inventory of stocks they hold

Why Market Makers Are Important#

Without market makers, you might place an order and wait indefinitely for another person to take the other side of your trade. Market makers ensure:

  • Immediate execution: Your trades can execute quickly
  • Tighter spreads: Competition among market makers keeps spreads narrow
  • Price stability: They absorb temporary supply/demand imbalances

When you place a market order, a market maker is often on the other side of your trade. They provide immediate liquidity in exchange for the spread.

Major Market Makers#

  • Citadel Securities
  • Virtu Financial
  • Two Sigma Securities
  • Susquehanna International Group

Brokers#

A broker (or brokerage firm) acts as an intermediary between you and the stock market. You can't trade directly on an exchange—you need a broker.

What Brokers Do#

  • Execute trades on your behalf on exchanges
  • Hold your securities in a brokerage account
  • Provide tools for research, analysis, and order placement
  • Handle settlement and administrative tasks
  • Offer educational resources for investors

Types of Brokers#

TypeFeaturesExamples
Full-ServicePersonal advice, research, higher feesMorgan Stanley, Merrill Lynch
Discount/OnlineSelf-directed, low/no commissionsFidelity, Charles Schwab, TD Ameritrade
Mobile-FirstApp-based, commission-freeRobinhood, Webull, SoFi

Choosing a Broker#

Most beginning investors use discount or mobile brokers because:

  • Commission-free stock trading is now standard
  • User-friendly platforms and apps
  • No minimum account requirements at many firms
  • Access to educational resources

Other Market Participants#

Regulators#

  • SEC (Securities and Exchange Commission): Primary U.S. securities regulator
  • FINRA (Financial Industry Regulatory Authority): Oversees brokers and dealers
  • Stock Exchanges: Self-regulatory organizations with their own rules

Analysts and Rating Agencies#

  • Research analysts study companies and make recommendations
  • Rating agencies assess bond creditworthiness
  • Their opinions can influence stock prices

Index Providers#

  • Companies like S&P Global, MSCI, and FTSE Russell create indices
  • Index inclusion/exclusion can significantly impact stock prices
  • They determine which stocks index funds must buy

How It All Connects#

Here's a simplified view of how a trade flows through the market:

  1. You decide to buy a stock
  2. Your broker receives your order
  3. Broker routes order to an exchange or market maker
  4. Market maker or seller takes the other side
  5. Exchange matches and records the trade
  6. Clearinghouse settles the transaction
  7. Shares appear in your brokerage account

All of this typically happens in fractions of a second for most retail orders!

Key Takeaways

  • Retail investors are individuals investing for personal goals
  • Institutional investors (mutual funds, pensions, hedge funds) manage large pools of capital
  • Market makers provide liquidity by always being willing to buy or sell
  • Brokers are intermediaries that execute your trades and hold your securities
  • Regulators oversee the market to protect investors
  • Understanding market structure helps you become a more informed investor