Stocks, each unit of which is called a share, represent ownership of a company. Stocks, owned either directly or through a mutual fund or ETF, will likely form the majority of most investor’s portfolios. 

Frequently Asked Questions
  • What’s the most expensive stock of all time?

    The most expensive publicly-traded share of stock of all time were the Class A shares of Berkshire Hathaway (BRK.A), Warren Buffet’s conglomerate and holding company as of January 2022. They hit $487,675 per share on Jan 18, 2022. It’s important to remember that this does not mean it is the most valuable company by stock value. The value of a company’s stock, or “market capitalization,” is determined by multiplying the price of its shares by the number of its shares.

  • What is the all time high of the Dow Jones Industrial Average (DJIA)?

    As of early 2022, the all-time closing high of the Dow Jones is 36,799.65 points, which it reached on January 4, 2022. The index’s all-time intraday high was 36,952.65, reached on Jan 5, 2022.

  • What are unrealized gains and losses?

    Unrealized gains or losses represent the amount you would gain or lose if you sold your investment, often a stock, at its current value. You “realize” these gains or losses when you actually sell the investment.

  • What is the difference between preferred stock and common stock?

    When people talk about stocks, they are usually referring to common stock, which is stock that usually gives voting rights in shareholder votes. Preferred stock almost never confers voting rights, but if a company only has enough money to pay some of its dividends, it has to pay preferred stock dividends first. In addition, in the event of a bankruptcy, preferred stockholders have priority over common stockholders on company assets.

  • What’s the difference between cyclical and non-cyclical stocks?

    Cyclical stocks are those that tend to rise and fall with the broader economy, falling when the economy is doing poorly and rising when the economy is doing well. Non-cyclical, often also called defensive stocks, tend have steadier performance that do better when the economy is down are down but peak less high during boom years.

Key Terms

charts_index_investing
Comparing Mid-Cap Indexes
Rear view of businesswoman looking at stock exchange market display screen board in downtown financial district
Types of Stocks
Person on sofa at home, trading online with tablet
How to Invest Online
Meme Stocks
What Are Meme Stocks, and Are They Real Investments?
A woman accepting a present and kiss from a male friend
How to Give Stocks as a Holiday Gift
Best Day Trading Courses
Best Day Trading Courses
Apple's 5 Most Profitable Lines of Business
LUPA Stocks
LUPA Stocks
Secured Overnight Financing Rate
Secured Overnight Financing Rate (SOFR) Definition and History
Close-up of logo for Amazon Prime service on a branded delivery truck.
Does Prime Day Impact Amazon's Stock (AMZN)?
Stock market numbers are displayed on multiple screens at the New York Stock Exchange
Best Undervalued Stocks for March 2024
A Nvidia sign is shown outside the company's headquarters
Best AI Stocks for March 2024
A person holds a phone displaying Amazon's stock price
Magnificent 7 Stocks: What You Need to Know
Couple listening to their financial advisor
How to Rebalance Your Portfolio
Street view of the Nasdaq building in New York
Nasdaq’s AI Order Type (Dynamic M-ELO): What to Know
Index Rebalancing
Index Rebalancing: What Every Investor Should Know
Financial investment, stock market and exchange, accounting concept
How to Invest in ESG
Young adult man using smart phone to monitor market and stock trading in AI
How to Invest In AI
a person sitting in an office in front of a laptop looking intently at the screen
How to Buy Stocks on eToro
Businessman reading financial stock market analysis
How to Buy Fractional Shares on Webull
Close-up of woman trading stock online on mobile phone
How to Buy Fractional Shares on Fidelity Investments
Woman using smartphone to trade fractional shares at a coffee shop
How to Buy Fractional Shares
Over the shoulder view of Asian woman holding smartphone, analyzing investment trading data on crypto graph with smartphone and laptop while working at home. Cryptocurrency, bitcoin, digital ledger
How to Automate Your Investing
Investing in the stock market
How to Invest in Web 3.0
A house on a shopping cart full of coins
How Does the Dividend Discount Model (DDM) Work?
Woman studying her trades on a laptop
Common Stock: What It Is, Different Types, vs. Preferred Stock
Debt/Equity Swap
What Is a Debt/Equity Swap? How It Works and Who Benefits
Preferred vs. Common Stock: What's the Difference?
People floating in currency symbol hot air balloons
Floating Stock: Definition, Example, and Why It's Important
S&P 500 Index
S&P 500 Index: What It’s for and Why It’s Important in Investing
Warren Buffett, chairman and CEO of Berkshire Hathaway Inc., participates in a panel discussion
How Does Warren Buffett Choose His Stocks?
Financial Data Analyzing
Finding Short Candidates With Technical Analysis
Income Stock: What it is, How it Works, Example
Efficient Market Hypothesis: Is the Stock Market Efficient?
Businessman analyzing report on the tablet.
Cyclical Stock: What It Is, Examples, Risk and Return Potential
Street with shops and restaurants in Shinjuku district in Tokyo, Japan
Tokyo Stock Exchange (TSE): Definition, History, How It Works
Preference Shares: Advantages and Disadvantages
Hand of a Stockbroker Buying and Selling Shares Online
Issued Share vs. Subscribed Share Capital: What's the Difference?
NASDAQ stock market displays at Times Square
What Are the Listing Requirements for the NASDAQ?
Business graph with arrows tending downwards.
Understanding Small-Cap and Big-Cap Stocks
Adjusted Closing Price: How It Works, Types, Pros & Cons
Aerial View Of Bulldozer On Sand
Basic Materials Sector: Definition, Examples, and Stocks
Clientele Effect: Definition, Theory, Examples
Banker with laptop meeting with client in bank branch office.
What Is a Depositary Receipt (DR)? Definition, Types and Examples
Dual Class Stock: Definition, Structure, and Controversy
Mid-Cap: Definition, Other Sizes, Valuation Limits, and Example
Preference Shares
What Are Preference Shares and What Are the Types of Preferred Stock?
Share Turnover: Definition, What It Signals, Formula, and Example
Cropped Image of Man Checking Stock Market on Mobile Phone
Theoretical Ex-Rights Price – TERP
Stock market data on digital display.
Cyclical vs. Non-Cyclical Stocks: What's the Difference?
Stock market graph chart.
Restricted Shares vs. Stock Options: What's the Difference?
Businessman Show Analyzing Report
What's the Most Expensive Stock of All Time?
Back Stop: Providing last-resort support or security in a securities offering for the unsubscribed portion of shares.
Back Stop: Definition, How It Works in Offering, and Example
Bearer Share: Definition, Example, Risks, and Benefits
CANSLIM Explained: What It Is and How It Works
Image of stock chart on mobile phone
Fractional Share: Definition, Examples, How To Buy & Sell
Businessman grabs head with business chart on screen
October Effect: Definition, Examples, and Statistical Evidence
Shareholder Register: Definition, What It Includes, and Example
Midsection Businessmen Analyzing Charts on Laptop in Office
Tracking Stock: Definition, Benefits, Risks, and Example
Porter's 5 Forces on Under Armour
Page Sources
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
  1. New York Stock Exchange (NYSE). "Berkshire Hathaway, Inc. BRK.A." Accessed Jan. 22, 2022

  2. Yahoo! Finance. "Dow Jones Industrial Average (^DJI). Historical Data." Accessed Jan. 14, 2022.

  3. U.S. Securities and Exchange Commission. "Stocks." Accessed June 28, 2021.