Systems & Society · Lesson 03
Stock Exchange Simulator
A stock market is where buyers and sellers trade ownership shares in companies — and prices move every second based on news, earnings, and investor confidence. Open the market below, watch prices respond to live headlines, and try to grow your $10,000 portfolio.
Before You Trade
A stock is a small piece of ownership in a company. When a company does well — good news, strong sales, a new product — more people want to own it, so the price rises. When something goes wrong, people sell, and the price falls. You make money by buying low and selling high.
The four companies are fictional but built to feel like real sectors you know: consumer tech, clean energy, retail, and pharmaceuticals.
Candlesticks show each price window’s open, high, low, and close. Long wicks mean uncertainty. Green candles closed above open; red candles closed below it.
The Simple Version
Think of stocks like rare trading cards. If a new set comes out and everyone wants Card X, the price goes up. If the card gets banned from tournaments, nobody wants it and the price drops.
Companies are the same. When TechSpark launches a hit phone, everyone wants a piece — the stock goes up. When a recall hits, people worry the company will lose money — so they sell and the price falls.
Your job is to predict which companies will get good news and buy before prices rise. Then sell when prices are high. But be careful — news is unpredictable.
The Deeper Version
Stock prices reflect the market's collective expectation of a company's future cash flows, discounted to their present value. A good earnings report isn't surprising if the market already "priced it in" — the stock might not move at all.
Notice in the simulator how price changes are larger for BioCore (pharma) than MegaMart (retail). That's volatility — binary events like FDA approvals or trial failures can swing pharma stocks by 15–20%, while stable retailers rarely move more than 5–8%.
Watch for the market-wide news events too — a Federal Reserve interest rate decision affects every sector simultaneously because it changes the cost of borrowing for all companies, adjusting their expected future cash flows at once.
Reflection Questions
- 1.When BioCore's drug failed FDA approval and the price dropped sharply, what do you think other investors were thinking? Why does fear spread through a market so quickly?
- 2.You started with $10,000. Did you end up with more or less? What decisions led to that outcome — luck, strategy, or both?
- 3.MegaMart is the most expensive stock per share ($221+) and GreenLeaf is cheaper ($67). Does buying a more expensive stock mean you're taking more risk? Why or why not?
- 4.In a real stock market, millions of investors make decisions simultaneously. How does that "crowd wisdom" make markets more — or less — accurate at setting prices?
- 5.(Advanced) In this simulation, you can see all the news before you trade. In real markets, some investors illegally trade using private information before it becomes public — called insider trading. Why do you think this is considered unfair and illegal?
Teacher Notes — Not for Student View
Facilitation Guide
Learning objectives
- Students understand that stock prices reflect supply and demand driven by expectations, not just current company value.
- Students can explain why news events cause price changes — and why different sectors react with different magnitudes.
- Students experience the emotional reality of investing: the tension of watching losses and the temptation to sell during drops.
- Students develop basic vocabulary: stock, share, portfolio, diversification, bull/bear market, volatility, dividend.
What NOT to over-explain
- Don't explain order books or bid/ask spreads. This simulator uses a simplified "last price" model. The mechanics of limit orders, market orders, and spreads are for a more advanced finance course.
- Don't push the formulas. P/E ratios, discounted cash flow, CAPM — these are grade-appropriate for an advanced economics class, not this introductory simulation.
- Don't over-correct emotional responses. When a student is frustrated that their stock dropped, that's the lesson. Let them sit with it, then ask why it happened.
Common misconceptions
- "A higher share price means a better company." Price per share is arbitrary — it reflects stock splits and history, not company quality. A $5 stock can be a better investment than a $500 stock. Focus on percentage change, not absolute price.
- "If I lose money I'm being robbed." In a market, your loss is someone else's gain (and vice versa). No money disappears — it changes hands. This is worth a brief discussion on market structure.
- "Good news always means the price goes up." If the market already expected good news, the price may have risen already. Stocks are forward-looking. Sometimes "good but not as good as expected" causes a drop.
Cross-subject connections
Pacing suggestions
- Single period (50 min): 5 min intro, 25 min simulator (speed 2× or 4×), 10 min debrief using reflection questions, 10 min connecting to real markets.
- Two periods: Day 1: Intro + 20 min simulator at speed 1× (realistic feel). Day 2: Compare portfolios, discuss strategies, introduce advanced concepts (volatility, diversification).
- Assessment option: After the session, ask students to write a short explanation of one trade they made — why they made it, what happened, and what they'd do differently.
Real-world company connections
The fictional companies are loosely inspired by real sectors — not specific companies. TechSpark evokes Apple/Google. GreenLeaf Energy evokes Tesla or NextEra Energy. MegaMart evokes Amazon or Walmart. BioCore Health evokes Pfizer or Johnson & Johnson. When drawing real-world parallels, stress that these are simplified analogies — real companies have far more complexity, competitive pressures, and financial structure.