Stock Exchanges: NYSE, Nasdaq & How They Work

How Stock Exchanges Work

A stock exchange is an organized marketplace where buyers and sellers trade securities under standardized rules. Exchanges provide the infrastructure for price discovery, order matching, trade execution, and settlement. Without them, buying and selling stocks would require finding a counterparty on your own, negotiating a price, and handling the transfer of shares and cash manually.

Every trade on an exchange follows a basic sequence: a buyer submits an order, a seller submits an order, the exchange's matching engine pairs compatible orders, and the trade executes. The executed price becomes the new market price, visible to all participants. This transparency is what separates exchange-traded secondary markets from over-the-counter venues where pricing can be opaque.

In the United States, the two dominant exchanges are the New York Stock Exchange (NYSE) and the Nasdaq. Together, they list the vast majority of publicly traded American companies and handle trillions of dollars in daily trading volume.

NYSE: The Auction Market

The New York Stock Exchange, founded in 1792, is the largest stock exchange in the world by market capitalization of listed companies (over $25 trillion). It operates as a hybrid auction market, combining electronic trading with human oversight from Designated Market Makers (DMMs).

DMMs are firms assigned to specific stocks on the NYSE floor. Their job is to maintain orderly trading by providing liquidity, managing the opening and closing auctions, and stepping in to stabilize prices during volatile periods. When there is a temporary imbalance between buy and sell orders, the DMM trades from their own inventory to bridge the gap.

The NYSE's opening auction is particularly significant. Each morning at 9:30 AM ET, DMMs collect all pre-market orders and determine a single opening price for each stock that satisfies the maximum number of orders. This process sets the tone for the trading day.

Major NYSE-listed companies include Berkshire Hathaway (BRK.B), JPMorgan Chase (JPM), Johnson & Johnson (JNJ), and Walmart (WMT). The exchange tends to attract established blue-chip companies that value the prestige of an NYSE listing.

Nasdaq: The Dealer Market

The Nasdaq, launched in 1971, was the world's first electronic stock exchange. It operates as a dealer market where multiple market makers compete to provide the best prices for each listed stock. Unlike the NYSE's single DMM per stock, Nasdaq stocks typically have 20 or more market makers quoting prices simultaneously.

This competition among market makers tends to produce tighter bid-ask spreads, particularly for heavily traded names. The Nasdaq is home to many of the world's largest technology companies, including Apple (AAPL), Microsoft (MSFT), Amazon (AMZN), Alphabet (GOOGL), and Nvidia (NVDA).

The Nasdaq operates three tiers:

• Nasdaq Global Select Market: The highest tier with the strictest listing requirements. Most large-cap tech stocks trade here.
• Nasdaq Global Market: Mid-tier with moderate requirements.
• Nasdaq Capital Market: The entry-level tier for smaller companies.

Auction vs Dealer: Key Differences

In practice, the trading experience for retail investors is nearly identical regardless of which exchange a stock is listed on. Your broker routes your order to the venue offering the best price under Regulation NMS (National Market System), which may or may not be the listing exchange.

Listing Requirements

Companies must meet specific financial and governance standards to list on an exchange. These requirements protect investors by ensuring a minimum level of financial viability and transparency.

NYSE listing requirements include:

• Aggregate pre-tax earnings of at least $10 million over the prior three years, with $2 million minimum in each of the two most recent years
• Minimum share price of $4.00
• At least 400 shareholders holding 100+ shares
• 1.1 million publicly held shares outstanding

Nasdaq Global Select Market requirements include:

• Minimum bid price of $4.00
• At least 1.25 million publicly held shares
• Market value of publicly held shares of at least $45 million
• Must meet one of several financial standards (income, equity, or total assets/revenue tests)

Companies that fail to maintain these standards face delisting. If a stock's price falls below $1.00 for 30 consecutive trading days on the Nasdaq, for example, the company receives a notice and has 180 days to regain compliance. Delisted stocks typically move to OTC markets where liquidity and transparency are significantly reduced.

Global Exchanges

U.S. exchanges dominate global equity trading, but significant markets operate worldwide:

• London Stock Exchange (LSE): Europe's largest, home to companies like Shell (SHEL) and AstraZeneca (AZN)
• Tokyo Stock Exchange (TSE): Asia's largest by market cap, listing Toyota (TM) and Sony (SONY)
• Shanghai and Shenzhen Stock Exchanges: China's primary markets, with restrictions on foreign investor access
• Euronext: Pan-European exchange operating in Paris, Amsterdam, Brussels, and Lisbon

For U.S. investors, foreign stocks are accessible through ADRs or international ETFs without needing accounts at foreign exchanges. An IPO on a foreign exchange may later cross-list on a U.S. exchange through an ADR program.

The Role of Technology

Modern exchanges execute trades in microseconds. High-frequency trading firms colocate their servers in the same data centers as exchange matching engines to shave microseconds off execution times. This technological arms race has driven bid-ask spreads to historical lows, benefiting all investors through lower implicit trading costs.

However, technology has also introduced new risks. The Flash Crash of May 6, 2010, saw the Dow Jones Industrial Average plunge nearly 1,000 points in minutes before recovering. This event led to the implementation of circuit breakers that halt trading when individual stocks or broad indices move too far, too fast.

FAQ

Does it matter which exchange a stock is listed on?

For most retail investors, no. Regulation NMS ensures your order is routed to the best available price across all venues. The listing exchange matters more for the company itself in terms of prestige, listing fees, and the specific market makers providing liquidity. You will not notice a practical difference in your trading experience.

Can a stock be listed on multiple exchanges?

In the U.S., stocks are listed on one primary exchange (NYSE or Nasdaq) but can trade on multiple venues. Internationally, dual listing is common. A company like Unilever trades on both the London Stock Exchange and the NYSE. This increases liquidity and gives investors in different time zones direct access.

What happens during an exchange outage?

Exchange outages are rare but do occur. On December 11, 2023, the NYSE experienced a technical issue that caused erroneous opening prints on dozens of stocks. When an exchange goes down, trading in affected stocks shifts to other venues. Brokers reroute orders, and backup systems activate. However, liquidity typically drops during outages, leading to wider spreads and more volatile pricing until normal operations resume.