Stock Market Explained: A Clear Guide for Investors

Stock Market Explained: A Clear Guide for Investors

The stock market is a network of exchanges where shares of public companies trade between buyers and sellers at prices set by supply and demand. In the United States, most trading happens on the NYSE and Nasdaq, which together list about 5,700 companies and handle roughly 15 billion shares a day. When someone says "the stock market was up 1.2% today," they usually mean an index like the S&P 500 moved that much, not that every listed company did.

The market matters because it is where ownership of productive businesses changes hands. Buying one share of Coca-Cola (KO) makes you a fractional owner of a company that sold 2.2 billion cases of beverages last quarter. The price you pay, and the fundamentals you inherit, decide your return over the next ten years.

Key Takeaways

• The U.S. stock market is made up of exchanges (NYSE, Nasdaq), regulators (SEC, FINRA), brokers, market makers, and the investing public.
• Regular hours run 9:30 a.m. to 4:00 p.m. Eastern, Monday to Friday, with 10 full-day closures for U.S. holidays in 2026.
• Prices are set by the last matched trade, not by company "value." A stock can trade at a P/E of 45 while earning the same per share as one trading at 10.
• Over 100 years, U.S. stocks have returned about 9.8% annualized before inflation, but individual decades have ranged from -0.9% (2000s) to +17.3% (1950s).
• Value investors filter the roughly 6,000 listed U.S. tickers down to a watchlist of 20 to 40 using specific metrics: ROIC above 15%, debt-to-equity under 1.0, earnings yield above 6%.
• "The market" in headlines usually means an index. The S&P 500 covers about 80% of U.S. equity market cap in just 500 names.
• Day-to-day moves are mostly noise. Over 90% of the 10-year return from a diversified index comes from earnings growth and dividends, not multiple expansion.

What the Stock Market Actually Is

A stock market is two things at once.

First, it is a primary market. When a private company files an S-1 and sells shares to the public for the first time, that is an IPO, and the cash goes to the company. In 2025 there were 156 U.S. IPOs, raising a combined $31.8 billion.

Second, it is a secondary market. After the IPO, those shares trade between investors. None of that money goes to the issuing company. When you buy 10 shares of Apple (AAPL), your dollars go to whoever sold those 10 shares. Apple itself is not involved in the transaction.

The secondary market is where 99% of daily volume happens. That distinction matters because it clarifies what a stock price is: it is the price at which the last share changed hands between two anonymous parties, not an official valuation of the business.

Who Sets the Price

Four groups determine the quoted price of a stock at any moment.

Market makers (Citadel Securities, Virtu, Jane Street) post continuous bid and ask prices. They earn a spread between the two. On AAPL, the spread is usually $0.01 on round lots.

Institutional investors (Vanguard, BlackRock, Fidelity, hedge funds) move size. A single BlackRock trade can be 200,000 shares. Their order flow dominates volume on large caps.

Retail investors place the remaining volume through brokers like Schwab, Fidelity, Robinhood, and Interactive Brokers. In 2024, retail made up about 23% of total U.S. equity trading volume, up from 10% in 2019.

High-frequency traders execute millions of small orders to capture fractions of a cent per share. HFT is estimated at 50% to 60% of volume on a typical day.

The exchange matches bids and asks using a limit order book, and the most recent matched price becomes "the price" you see on your broker's app.

Stock Market Hours and Holiday Closures

U.S. regular trading hours are 9:30 a.m. to 4:00 p.m. Eastern, five days a week. There is also a pre-market session (4:00 a.m. to 9:30 a.m.) and an after-hours session (4:00 p.m. to 8:00 p.m.), though liquidity in both is thin.

The NYSE and Nasdaq close for 10 full days each year. On three other days, they close early at 1:00 p.m. Eastern (the day after Thanksgiving, Christmas Eve, and the day before Independence Day when it falls on a weekday).

Bond markets follow a different schedule. They close for Columbus Day and Veterans Day while stocks stay open.

Indices: What "The Market" Means in Headlines

When CNBC says the market is down, they mean an index.

S&P 500: 500 large-cap U.S. companies, market-cap weighted. Captures roughly 80% of U.S. equity market capitalization. The top 10 holdings (led by Apple, Microsoft, Nvidia, Amazon, Meta, Alphabet) make up about 36% of the index.

Dow Jones Industrial Average: 30 large U.S. companies, price-weighted. UnitedHealth (UNH) has more weight in the Dow than Apple because UNH's share price is higher, even though Apple's market cap is 7x larger.

Nasdaq Composite: All 3,300+ stocks listed on the Nasdaq exchange. Tech-heavy. Microsoft, Apple, Nvidia, and Amazon drive most of the index movement.

Russell 2000: 2,000 small-cap U.S. companies. Used as a proxy for the small-cap segment. Historically more volatile than the S&P 500 (standard deviation of 19% vs. 15%).

A value investor does not buy "the market." We buy specific tickers based on specific data. But indices are useful as a benchmark and as a gauge of sentiment.

What Moves Stock Prices

Four forces set individual stock prices in descending order of long-term importance.

Earnings and cash flow. Over a 10-year window, stock prices track earnings per share growth about 80% of the time. Microsoft (MSFT) grew diluted EPS from $2.10 in 2015 to $11.80 in 2024. The stock went from $55 to $420. The math lines up.

Interest rates. When the 10-year Treasury yield rises, future cash flows are discounted at a higher rate, and growth stocks especially lose value. A 1% rise in rates historically compresses the S&P 500 P/E multiple by about 1.5 turns.

Sentiment and flows. Passive ETF flows alone drove about 40% of the 2023 and 2024 market rally. Retail sentiment, margin debt, short interest, and put/call ratios all shift prices short term.

Unexpected news. An earnings miss, a lawsuit, a regulatory change, a CEO departure. These move the stock immediately and can dominate a single day.

Day one of any position, you are exposed to all four. Day 1,000 of a Coca-Cola position, the first factor dwarfs the others.

How Value Investors Use the Stock Market

Value investing treats the stock market as a supplier, not an authority. Benjamin Graham's "Mr. Market" allegory captures it: a business partner shows up every day with a quote, sometimes depressed, sometimes manic, and we decide whether to trade with him.

Our process at ValueMarkers follows four steps.

Screen. We filter 100,000 listed tickers down to a shortlist using the screener. Typical value filters: P/E under 20, ROIC over 15%, debt-to-equity under 1.0, earnings yield above 6%.

Analyze. For each finalist, we read the 10-K, calculate intrinsic value using the DCF calculator, and compare the result to the current price.

Wait. A stock worth $120 trading at $140 is not a buy. We maintain a watchlist and wait for margin of safety, typically 30% below intrinsic.

Hold. Once the purchase is made, we judge progress by the underlying business, not the price quote. If earnings grow and ROIC stays above 15%, the position is working even if the price sits flat for two years.

This is why headlines like "market down 2%" or "market hits new high" do not drive our decisions. The market is a pricing mechanism. The business is the investment.

When the Stock Market Falls

Bear markets (declines of 20% or more from peak) happen on average every 7 to 8 years. Since 1945, the S&P 500 has had 13 bear markets. Average drawdown: 33%. Average duration: 14 months. Average recovery time back to the prior peak: 23 months.

The 2008 crash took the S&P 500 from 1,565 to 676, a drop of 57%. Full recovery by March 2013.

The 2020 COVID crash dropped 34% in 33 days and fully recovered in 148 days, the fastest recovery on record.

The 2022 bear market bottomed down 25% from the peak. Full recovery by January 2024.

For a value investor, a falling market is a shopping catalog. The same businesses are on sale. Buffett bought $5 billion of Goldman Sachs in October 2008 at $115 a share (GS closed 2024 at $535). The discipline is not predicting the bottom; it is having cash and a watchlist.

Trading vs. Investing

The stock market supports both, but the distinction matters.

Trading focuses on short-term price moves. Holding period: seconds to weeks. Tools: technical analysis, momentum, options. Win rate typically 55% is considered excellent. Taxes: short-term capital gains, up to 37% federal.

Investing focuses on multi-year ownership of businesses. Holding period: 3 to 20+ years. Tools: fundamental analysis, valuation models, quality screens. Win rate can be lower while returns are higher because winners compound. Taxes: long-term capital gains, up to 20% federal.

Warren Buffett's sold position count from 2004 to 2024 averaged 6 per year. His average holding period for core positions is over 20 years. That is investing.

A day trader might take 40 positions a day. That is trading.

ValueMarkers is built for the second group. The tools exist to identify businesses that will compound. Everything from the guru tracker to the VMCI Score is designed around multi-year ownership.

Further reading: SEC EDGAR · Investopedia

Why stock market hours Matters

This section anchors the discussion on stock market hours. The detailed treatment, formula, and worked examples appear in the body of this article above. The points below summarize the most important takeaways for value investors who want to apply stock market hours in real portfolio decisions. ValueMarkers exposes the underlying data on every covered ticker via the screener and stock profile pages, so the concepts in this article translate directly into actionable filters.

Key inputs for stock market hours

See the main discussion of stock market hours in the sections above for the full treatment, including the inputs, the calculation methodology, the typical sector benchmarks, and the most common pitfalls to avoid. The ValueMarkers screener lets value investors filter the full universe of 100,000+ stocks across 73 exchanges using stock market hours alongside the rest of the 120-indicator composite, with sector percentiles and historical trends shown on every stock profile.

Sector benchmarks for stock market hours

See the main discussion of stock market hours in the sections above for the full treatment, including the inputs, the calculation methodology, the typical sector benchmarks, and the most common pitfalls to avoid. The ValueMarkers screener lets value investors filter the full universe of 100,000+ stocks across 73 exchanges using stock market hours alongside the rest of the 120-indicator composite, with sector percentiles and historical trends shown on every stock profile.

Frequently Asked Questions

what happens if the stock market crashes

If the stock market crashes, share prices fall sharply (typically 20% or more) within weeks or months, and account values drop accordingly. Historically every U.S. crash has recovered and exceeded its prior peak within 2 to 5 years. The practical risk is forced selling: if you need the money during the drawdown, you crystallize the loss.

what time does the stock market open

The NYSE and Nasdaq open at 9:30 a.m. Eastern Time, Monday to Friday. Pre-market trading starts at 4:00 a.m. Eastern but has thin volume and wider spreads. Regular hours are when institutional volume concentrates and price discovery is most efficient.

are stock markets closed today

U.S. stock markets are closed on 10 federal holidays and every Saturday and Sunday. If today is one of those 10 dates, yes. Check the NYSE 2026 calendar: the major closures are New Year's Day, MLK Day, Presidents' Day, Good Friday, Memorial Day, Juneteenth, Independence Day, Labor Day, Thanksgiving, and Christmas.

what time does the stock market close

Regular session closes at 4:00 p.m. Eastern Time. After-hours trading runs from 4:00 p.m. to 8:00 p.m. but with much lower liquidity. On the day after Thanksgiving, Christmas Eve, and sometimes July 3, the close is moved to 1:00 p.m. Eastern.

when does the stock market open

The U.S. stock market opens at 9:30 a.m. Eastern on every weekday except the 10 designated holidays. In 2026, the first trading day is Friday, January 2, because January 1 (Thursday) is closed for New Year's Day. Futures markets trade nearly around the clock, giving a rough preview of the open.

why is the stock market down today

The stock market can be down on any given day for four reasons: disappointing economic data (jobs, inflation, GDP), an earnings miss from a large index constituent, a rise in interest rate expectations, or broad risk-off sentiment tied to geopolitics. On most days the drop is 1% or less and represents noise rather than a shift in fundamentals. Check the 52-week range and 10-year chart before reacting.

Ready to stop watching the ticker and start analyzing businesses? Compare ValueMarkers against other platforms on our compare page and see how our 120 indicators stack up against the tools you currently pay for.

Written by Javier Sanz, Founder of ValueMarkers. Last updated April 2026.

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Disclaimer: This content is for informational and educational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any security. Past performance does not guarantee future results. Consult a licensed financial advisor before making investment decisions.