Common Stock

Also known as: Shares, Ordinary shares, Equity

A fractional ownership stake in a company — with voting rights, dividend claims and unlimited upside.

4 min read · 650 words · Updated

1 · SnapshotThe one idea to remember
Key intuition: a stock is not a lottery ticket or a line on a chart — it is a slice of a real business. Its long-run value follows the cash the business can generate.
2 · BeginnerWhat is it, really?

A share of common stock is exactly what the name says: a share of a company. If a company is split into 100 million shares and you own one million of them, you own 1% of the business — 1% of its factories, its brands, its bank account and, most importantly, its future profits.

You can make money in two ways. The company may pay out part of its profit as a dividend, and the market price of the share itself may rise. Neither is guaranteed: stock prices move every second the market is open, driven by profits, interest rates, and the mood of millions of buyers and sellers.

Shareholders are last in line. If the company fails, lenders and bondholders get paid first, and shareholders receive whatever is left — often nothing. In exchange for taking that risk, shareholders keep everything that remains after debts are serviced, which is why equities have historically out-earned safer assets over long horizons.

P&L of holding one share versus the price paid (dividends not shown).
CostLong stockShare priceProfit / loss

Point at a line to pick it out from the others.

What you pay, and what the company ever pays you
Youthe buyerAnother investorthe sellerThe companythe issuer1The price, plus commission2The shares5A buyer pays you, not thecompany3A dividend, only if declared4One vote per share

a paymentsomething deliveredonly if a condition is metnot a payment

Two separate relationships, and only one of them involves money moving between you and the company. The person on the other side of your trade is another investor; the company is not selling you anything.

The trade itself

  1. You → Another investor You pay the agreed price for the shares and your broker's charge on top. Not a penny of it reaches the company: it is a second-hand purchase from whoever wanted out.
  2. Another investor → You You now own a fraction of the company, bought from somebody who no longer wanted it.

For as long as you hold them

  1. The company → You A decision of the board, never an obligation. A company can cut it, skip it or never pay one, and none of that is a default.
  2. The company → You Not a payment. It is the only formal say you have, and on most holdings it is worth less than the time it takes to cast.

When you sell

  1. You → Another investor Your entire return is the dividends you collected plus whatever the next buyer will pay. The company is indifferent to your exit.
How the trade settles once it is agreedafter the trade
YouClearing housestands in betweenThe seller1The trade is novated4The record date runs onsettlement2Cash, net of the day3The shares, against payment

a paymentsomething deliveredonly if a condition is metnot a payment

None of this changes what you paid or what you own. It decides who carries the risk in the days between.

The same second

  1. You → Clearing house One contract becomes two: the clearing house is buyer to every seller and seller to every buyer, so you are never exposed to a stranger.

One or two days later

  1. Clearing house → The seller A broker that bought and sold the same stock all day delivers only the difference.
  2. The seller → You Neither side can be paid without delivering. The United States and Canada moved to one day after trade in May 2024; much of Europe settles on the second day.

Why the gap matters to you

  1. Clearing house → You Whether you are the holder entitled to a dividend or a vote depends on when the trade settled, not on when you agreed it.
Asset class
Cash equities
Instrument type
Ownership claim
Traded
Exchange (listed) or private
Typical users
Everyone — retail to pension funds

Which risks decide the outcome

Not how risky this is, and not a rating — there is deliberately no total. It says which of five failure modes drives what happens here, in the same order on all 129 products so they can be compared. This publication's own reading; see the notice below.

  • Marketdecides it
  • Creditmatters
  • Liquiditymatters
  • Fundingbarely applies
  • Operationalbarely applies

What decides it here. Market risk, and it is the whole point: you own the residual after everybody else has been paid. Credit only matters at the end, where equity is wiped before any lender loses a penny.

What the five mean, and which one decides where →

3 · IntermediateHow it works in practice

Rights that come with the share

  • Residual claim on profits and, in liquidation, on assets after all creditors.
  • Voting rights — typically one vote per share on directors, mergers and major decisions.
  • Limited liability — you can lose your purchase price, never more.
  • Pre-emption rights in many jurisdictions: the right to participate in new share issues before outsiders.

How trading actually works

Listed shares trade on exchanges in a central limit order book: buyers post bids, sellers post offers, and trades print where they cross. The difference between the best bid and best offer — the spread — plus commissions and market impact form your real cost of trading. Settlement (the actual exchange of shares for cash) usually happens one business day after the trade (T+1 in the US, T+2 in much of Europe).

What moves the price

In the short run: order flow, news, index flows, positioning. In the long run: earnings and the rate used to discount them. A useful decomposition of realised equity returns is dividend yield + earnings growth ± change in valuation multiple.

Worked example: you buy 100 shares at $50 ($5,000). The company pays $1.50/share in dividends over the year and the price ends at $54. Your return is (54 − 50 + 1.50) / 50 = 11% — 8% from price, 3% from dividends.
4 · AdvancedPricing & valuation

Valuation: discounting the residual claim

The price of a share is the present value of expected cash flows to its holder. The dividend discount model (DDM) with constant growth \(g\) and required return \(r\):

$$ P_0 \;=\; \sum_{t=1}^{\infty} \frac{\mathbb{E}[D_t]}{(1+r)^t} \;=\; \frac{D_1}{r - g} \qquad (r > g) $$
What the symbols mean
  • Pa price, or a present value
  • ta point in time
  • Ean expected value
  • Dduration: how far a bond's cash flows sit in the future
  • rthe interest rate, per year
  • ga growth rate, per year

In practice, analysts discount free cash flow to equity or use a two-stage model (explicit forecasts, then a terminal value). The required return \(r\) is commonly estimated with the CAPM:

$$ r \;=\; r_f + \beta \,\big(\mathbb{E}[R_m] - r_f\big) $$
What the symbols mean
  • rthe interest rate, per year
  • betahow much a holding moves with the market
  • Ean expected value
  • Ra return

where \(\beta\) measures the stock's sensitivity to market moves. Multiples (P/E, EV/EBITDA) are shorthand for the same discounting exercise under standardised assumptions.

Risk decomposition

Single-stock returns decompose into market (systematic) and idiosyncratic components, \(R_i = \alpha_i + \beta_i R_m + \varepsilon_i\). Only systematic risk is rewarded in equilibrium; idiosyncratic risk is diversifiable and priced at zero in the CAPM limit.

Corporate actions and the price

On the ex-dividend date the price drops by roughly the dividend amount; splits rescale price and share count with no value effect; buybacks shrink the share count, mechanically raising per-share metrics. Arbitrage keeps these relations tight.

The formulas above are standard textbook formulations, simplified for teaching. They explain the mechanism — they are not a valuation tool, and they will not reproduce a dealer’s price.

5 · Desk notesHow practitioners think about it
Practitioner note: equity is economically a call option on the firm's assets struck at the face value of its debt (Merton's model) — which is why deeply distressed equity behaves like an out-of-the-money option: small asset-value changes produce violent percentage moves.

Now say it back

Close the page and give Common Stock in four sentences. It takes a minute and it is the only way to find out whether reading it was enough.

  1. Who wants what — two parties wanted opposite things badly enough to write it down.
  2. What the contract obliges, and when — not the payoff; the obligation.
  3. Where the money comes from — name the source, or you have described a hope.
  4. What makes it lose — the ordinary way, not the dramatic one.

Do it with a clock → · why these four

Put Common Stock beside any other instrument →

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Where this instrument shows up elsewhere

Information and education only. Every page, figure and calculator on this site exists to explain how financial instruments work. Nothing here is investment, tax or legal advice, a recommendation, or a valuation you can rely on. Full disclaimer