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MARKETS

Education is the Markets family’s free school — a progressive SPY options course in plain English, from “should you trade at all?” to reading the live board it teaches, the SPY Sheet.

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EXCHANGES AND MARKET HOURS

Lesson 10 of 72 · 5 min read · Stage 1 · Markets, Ownership & SPY · Updated Oct 21, 2026
STAGE 1 — Markets, Ownership & SPY · Prerequisite: COMPANIES, IPOs, AND WHY PRICES MOVE
TL;DR
  • Stocks trade on exchanges — organised marketplaces (SPY lists on NYSE Arca) that match buyers and sellers and publish every price.
  • The regular session is 9:30am–4:00pm Eastern, weekdays: that’s when the full crowd is in and spreads are at their tightest.
  • Pre-market and after-hours sessions exist, but they’re thin: fewer participants, wider spreads, jumpier prices. Beginners use regular hours.

Where shares actually change hands, and why this course lives inside 9:30–4:00 Eastern. An exchange is an auction house with very strict manners. During the main sale (regular hours), the room is packed, every bid is public, and prices move a penny at a time. Before and after the main sale, a side room stays open with a handful of traders — the same goods, but worse prices, because there’s hardly anyone to bid against you. This course teaches you in the main room.

Market-hours timeline · diagram · One main room (regular session) and two side rooms, all in Eastern time.

THE TAKEAWAYS

  • An exchange’s job is matching and record-keeping: it pairs your buy with someone else’s sell, prints the price for everyone to see, and enforces the rules of the room.
  • Regular hours — 9:30am–4:00pm ET — are when institutions, funds and everyone else are present at once. That depth is what keeps SPY’s spread in penny-class territory.
  • Extended hours (pre-market from as early as 4:00am ET at many brokers; after-hours to about 8:00pm ET) trade the same tickers with a fraction of the participants — moves exaggerate and fills worsen.
  • The clock that matters is Eastern, whatever your timezone says. The open, the close and market news all run on it: 9:30am ET is 8:30am Central, where this course is written.
RUSTY’S RULE
Beginners trade regular hours only: 9:30–4:00 Eastern. Thin rooms are a tax on the new — let other people pay it.

WORKED EXAMPLE — STEP BY STEP

  1. Read the timeline graphic: side rooms 4:00–9:30am and 4:00–8:00pm ET; main room 9:30am–4:00pm ET. The SPY Sheet refreshes through the regular session because that’s the session that counts.
  2. Same stock, two rooms. In the main room, SPY’s spread is typically a cent: State Street reports a 30-day median bid/ask spread that rounds to 0.00% of price (Oct 14, 2026). In a thin pre-market, the same ticker can show spreads many times wider.
  3. Do the penny maths: buy at the ask and sell at the bid, and the spread is your instant cost. One cent on $771 is a rounding error; a 15-cent pre-market spread is a real toll — paid before your idea even starts.
  4. And overnight: the market closes, news doesn’t. Earnings, geopolitics and the rest of the world’s session pile up, and the 9:30am open is where the pile gets priced — which is why opens can gap. Stage 3 reads gaps properly; here, just respect them.
THE TRAP — THE 6AM ‘OPPORTUNITY’

A stock ‘pops’ at 6:15am on a headline. In the side room there are few sellers, the spread is wide, and a market buy fills at the top of a spike that the main room fades by 10am. You weren’t wrong about the news — you were early, alone, and charged for both. Regular hours wouldn’t have made the idea good; they’d have made the price honest.

LIQUIDITY IS A PROPERTY OF THE CROWD, NOT THE TICKER

Liquidity — how easily you can trade at a fair price — belongs to the room, not the stock. SPY is the same fund at 6am and 10am; the crowd is different. Every later lesson in this course quietly assumes main-room conditions: penny spreads, deep books, honest fills. Trade outside them and the lessons’ numbers stop describing your reality.

COMMON BEGINNER MISTAKES

  • Using market orders in extended hours — a wide spread plus a thin book is the worst fill combination there is.
  • Forgetting the timezone conversion: ‘the open’ is 8:30am Central, not 9:30.
  • Treating a pre-market spike as the day’s verdict. The main room regularly overrules the side room.
  • Watching prices at midnight and calling it research. The market you can actually trade reopens at 9:30 ET.

CHECK YOURSELF

Q1. The US regular session runs…

Q2. Extended-hours trading is riskier for beginners mainly because…

Q3. State Street’s reported 30-day median bid/ask spread on SPY rounds to…

DO IT — THE TWO ROOMS

Tomorrow, check SPY’s price once before 9:30am ET (note the time, and any spread your app shows) and once at 10:30am ET. Journal both. The difference between the side room and the main room is the lesson — see it once with your own eyes and you’ll never need to be told again.

Download this lesson’s cheat sheet (PDF)

STAGE 1 — MARKETS, OWNERSHIP & SPY — ALL 7 LESSONS

  1. 8WHAT A SHARE ACTUALLY IS5 min read
  2. 9COMPANIES, IPOs, AND WHY PRICES MOVE5 min read
  3. 10EXCHANGES AND MARKET HOURSYOU ARE HERE
  4. 11WHAT AN INDEX IS — AND ISN’T4 min read
  5. 12WHY THIS COURSE TRADES SPY6 min read
  6. 13BULLS, BEARS, AND MARKET WEATHER5 min read
  7. 14THE SPY SHEET — A FIRST LOOK6 min read