This is for learning only. Nothing on this site is financial advice.

Explainers

The stock market, explained the way a friend would explain it — not a textbook.

Start from the top if you're brand new, or jump straight to whatever you're curious about.

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Every explainer

Beginner

What Is a Stock, Really?

Why a company sells tiny pieces of itself, and what you get when you buy one.

4 minRead →

Beginner

How the Stock Market Works

What people actually mean when they say "the market is up" today.

5 minRead →

Beginner

How to Actually Buy a Stock

Apps, accounts, and the basic steps to buying your first share.

4 minRead →

Beginner

Don't Put All Your Eggs in One Basket

Why spreading your money around is one of the smartest moves you can make.

4 minRead →

Beginner

Why Starting Early Is a Superpower

How your money can grow on its own the longer you leave it alone.

4 minRead →

A Bit Trickier

How to Read a Stock Chart

What all those lines, colors, and bars actually mean.

5 minRead →

Beginner

Stocks vs. ETFs — What's the Difference?

The main ways people invest, explained with everyday examples.

4 minRead →

Beginner

7 Mistakes New Investors Make

The traps almost everyone falls into — and how to dodge them.

4 minRead →

Beginner

Word Bank (Glossary)

Every confusing term on this site, explained in one place.

ReferenceRead →

Beginner · 4 min read

What Is a Stock, Really?

⚡ Quick Hits

🍋 A stock = a tiny owned piece of a real company.
💵 Price = whatever people are willing to pay right now.
🏢 Companies "go public" (IPO) to start selling shares to anyone.

Your friend's lemonade stand is doing great. She wants to open 5 more, but needs cash for cups and lemons. So she says: "Give me $10 now, and you own a small piece of my business. If it grows, your piece grows too."

That's a stock. A stock (aka a share) is a tiny slice of a real company — Nike, Apple, a game studio, whatever. Buying one means you actually own part of that business, not just a number on a screen.

📈

Price goes up when...

The company does something people are excited about, and more people want to buy shares than sell them.

📉

Price goes down when...

The company disappoints people, and more people want to sell their shares than buy new ones.

Big idea: You're buying a real business, not a random number. If it does well over time, your slice usually becomes worth more.

How does a company even sell shares?

Most companies start private, owned just by the founders. Once they're big enough, they can "go public" — called an IPO — which means anyone can now buy shares. That's the moment a company shows up on the stock market for the first time.

🧠 Quick Check

If you buy one share of a company, what do you actually own?

Next up: How the Stock Market Works →

Beginner · 5 min read

How the Stock Market Works

⚡ Quick Hits

🏬 "The market" = exchanges like the NYSE and Nasdaq where shares trade all day.
📊 An "index" is a group of stocks tracked as one number.
⚖️ Prices move purely on supply and demand — no one sets them by hand.

The "stock market" isn't one building — it's a nonstop marketplace (an exchange) where people trade shares all day. Two of the biggest: the New York Stock Exchange and the Nasdaq.

What's an "index"?

When someone says "the market was up today," they mean an index moved — a group of stocks tracked together as one number, like a class average instead of one grade.

🇺🇸

S&P 500

~500 of the biggest U.S. companies. The one people mean most by "the market."

🏭

Dow Jones

30 big, well-known companies.

💻

Nasdaq

Leans heavily toward tech companies.

So "stocks fell 1% today" usually means one of these group averages dropped — not that every single stock fell by that much.

Who decides the price?

Nobody. It's pure supply and demand — more buyers than sellers pushes price up, more sellers than buyers pushes it down. This happens thousands of times per second while markets are open.

Good to know: U.S. markets are open 9:30am–4:00pm ET on weekdays. Trading happens outside those hours too, just quieter and jumpier.

🧠 Quick Check

What does it actually mean when the news says "the market was up 1% today"?

Next up: How to Actually Buy a Stock →

Beginner · 4 min read

How to Actually Buy a Stock

⚡ Quick Hits

📱 You need a brokerage app to trade — free and takes ~10 min to set up.
⚡ Market order = fast, no price control. 🎯 Limit order = price control, might not fill.
🔍 Trading is usually free, but check for expense ratios and spreads.

You can't buy a share straight from a company — you need a brokerage, an app or website allowed to trade stocks for you.

Two ways to place an order

⚡

Market order

"Buy it right now, whatever the price is." Fast, but you don't control the exact price you pay.

🎯

Limit order

"Only buy if it drops to this price." You control the price, but it might never trigger.

Watch out for fees

📄

Expense ratios

A small yearly fee some funds charge automatically, taken right out of your returns.

↔️

Bid-ask spread

A tiny gap between the buy and sell price — you pay it without really noticing.

Big idea: Even a small 1% fee adds up a lot over many years. Always check the fees before you invest in something.

If you're under 18: Most brokerages legally require you to be 18+ to open an account solo. You'll need a custodial account instead — opened by a parent or guardian, with you as the beneficiary. Ask them to open one with you; it's the normal way teens get started.

🧠 Quick Check

You want your trade to happen right now, even if you don't control the exact price. Which order do you use?

Next up: Don't Put All Your Eggs in One Basket →

Beginner · 4 min read

Don't Put All Your Eggs in One Basket

⚡ Quick Hits

🥚 One stock = risky. Many stocks = diversification = smoother ride.
🛡️ It doesn't stop losses, but it stops one bad company from wiping you out.
⏳ Money you need soon should be safer; money you won't touch for years can handle more risk.

Every investment carries some risk — it could lose value instead of gaining it. That's normal. The goal isn't zero risk; it's a level you're comfortable with, in exchange for a shot at growth.

🎯

1 stock

Put it all in one company and have a bad year? You lose big. All eggs, one basket.

🧺

500 stocks

Spread the same money across hundreds of companies — one bad one barely moves the needle.

That's called diversification. It won't make you risk-free, but it protects you from one single disaster wiping you out.

Keep in mind: Just because something went up in the past doesn't guarantee it'll keep going up. "Markets grow over time" is a pattern, not a promise.

🧠 Quick Check

Why do investors spread their money across many different stocks instead of just one?

Next up: Why Starting Early Is a Superpower →

Beginner · 4 min read

Why Starting Early Is a Superpower

⚡ Quick Hits

🔁 Compounding = your money earns money, then that new money earns money too.
🕰️ Time matters more than the amount you start with.
🐢 Starting small and early usually beats starting big and late.

Compounding is one of the coolest ideas in investing. Invest $1,000 and it grows 8% in a year? You now have $1,080. Next year, that 8% applies to $1,080 — not just your original $1,000. You earn more without adding a single extra dollar.

🐣

Person A

Invests $200/mo starting at 16. Stops after 10 years. Money grows untouched for decades.

🧑

Person B

Waits until 26 to start. Invests $200/mo for 20 straight years — way more total money in.

Even though Person B put in way more money overall, Person A often ends up with more by retirement — just because their money had more years to grow on its own.

Big idea: Time matters more than the amount you start with. Starting small and early usually beats starting big and late.

🧠 Quick Check

Person A starts investing at 16, Person B waits until 26 — same monthly amount. Who usually ends up ahead by retirement?

Next up: How to Read a Stock Chart →

A bit trickier · 5 min read

How to Read a Stock Chart

⚡ Quick Hits

🕯️ Candlesticks show price movement for a day/hour/etc.
📊 Volume shows how many shares traded — bigger volume = stronger signal.
📈 Moving averages smooth out the noise to show the bigger trend.

A stock chart is just a picture of price over time — but a few details tell you way more than the line alone.

🕯️

Candlesticks

Each bar shows price movement for that period. Red/filled = ended lower. Green/hollow = ended higher.

📊

Volume

Bars at the bottom show shares traded. Big move + high volume = a lot of people were involved.

📈

Moving averages

A smoothed line averaging price over the last 50 or 200 days — shows the trend, not the noise.

Heads up: Charts show what already happened, not what will happen next. Helpful clue, not a fortune-telling tool.

🧠 Quick Check

A stock jumps in price on unusually high trading volume. What does that usually suggest?

Next up: Stocks vs. ETFs — What's the Difference? →

Beginner · 4 min read

Stocks vs. ETFs — What's the Difference?

⚡ Quick Hits

🎯 Stock = one company. Exciting, but risky.
🎁 ETF = a variety pack of companies in one purchase. Low fees, easy diversification.
🧑‍💼 Mutual fund = similar to an ETF, but managed and priced once a day.

There are a few main ways to invest, and each solves a different problem.

🎯

Individual stocks

Shares in one company, like just Nike. Most exciting, also riskiest — tied to how that one company does.

🎁

ETFs

A variety pack — one purchase gives you a mix of lots of companies. Trades all day, usually low fees.

🏦

Mutual funds

Same mixed-basket idea, but priced once a day and often managed — can mean higher fees.

Common starting point: A lot of beginners start with a broad ETF for most of their money, then add individual stocks later once they're more comfortable researching companies.

🧠 Quick Check

What's the main advantage of an ETF over buying one individual stock?

Next up: 7 Mistakes New Investors Make →

Beginner · 4 min read

7 Mistakes New Investors Make

⚡ Quick Hits

😱 Most beginner mistakes come from emotion, not bad math.
📝 A simple plan — even one sentence — fixes most of them.

Panic-selling. Selling out of fear when prices drop, locking in a loss.

Chasing hype. Buying whatever's trending without understanding the company.

Not diversifying. Putting everything into one stock or sector.

Ignoring fees. Not checking costs that quietly eat into returns.

Trying to "time" the market. Even pros can't reliably predict the perfect moment.

Investing money you need soon. Short-term savings shouldn't be at risk.

No plan. Buying/selling based on feelings instead of clear goals.

Big idea: Most of these come from emotion, not from being bad at math. Having a simple plan — even a one-sentence one — helps a ton.

🧠 Quick Check

Panic-selling right after prices drop is risky mainly because...

Reference

Word Bank

Tap a word to see what it means.

A stretch of time where prices are generally going up and people feel optimistic.

A stretch of time where prices are generally falling and people feel pessimistic.

Some companies pay out a little bit of their profit directly to shareholders, usually every few months. That payment is a dividend.

The total value of a company, based on its share price times how many shares exist. Used to compare how "big" companies are.

A quick way to check if a stock seems expensive or cheap compared to how much profit the company actually makes.

How much and how fast a price jumps around. High volatility means big swings up and down.

How easily you can buy or sell something without messing up its price. Popular stocks are easy to trade — that's "high liquidity."

All the investments you own put together — stocks, ETFs, whatever else.

How you split your money between different types of investments, based on your goals and how much risk you're okay with.

Shares of a big, well-known, financially solid company with a long track record — think Coca-Cola or Microsoft.