There are three main ways to tell your broker to buy or sell a stock. Each one makes a different trade-off between speed and price control.
Market order = "I'll pay whatever for this concert ticket right now." Limit order = "I'll only pay $50 max for a ticket — if it's more, I'll wait." Stop order = "If the ticket value drops below $40, sell mine automatically before it gets worse."
When to Use Each
Market order: When you want to buy or sell immediately and the stock is liquid (lots of trading volume). Good for large-cap stocks like AAPL or VOO.
Limit order: When you want price control. Essential for less-liquid stocks where the price might jump. You set the max you'll pay.
Stop order (stop-loss): To protect yourself from big losses. "If this stock drops to $40, sell it." It's like an automatic emergency exit.
For most beginners buying popular ETFs like VOO or QQQ, a market order during regular hours is perfectly fine. The price you see is very close to the price you'll get. Use limit orders for smaller, less-traded stocks.
Trading Hours
The US stock market isn't open 24/7. There are specific windows when you can trade — and the rules change depending on the session.
Why Does This Matter?
Regular hours (9:30 AM - 4:00 PM ET): This is when most trading happens. Prices are most accurate, spreads are tightest, and orders fill fastest.
Pre-market (4:00 - 9:30 AM ET): Lower volume, wider spreads, and prices can swing wildly on overnight news.
After-hours (4:00 - 8:00 PM ET): Same issues as pre-market. Big price moves often happen here when companies report earnings.
Pre-market and after-hours trading is riskier: fewer buyers and sellers means wider bid-ask spreads, more volatile price swings, and your order might not fill at the price you expect. Beginners should stick to regular hours.
The market is closed on weekends and US holidays. If you place an order on Saturday, it won't execute until Monday at 9:30 AM ET. For Beijing time, regular hours start at 9:30 PM — a night-owl schedule.
How to Buy a Stock: 5 Steps
Buying your first stock is simpler than you think. Here's the entire process from zero to "I own shares."
Step-by-Step
Open a brokerage account: This is your "stock store" account. Popular choices: Fidelity, Charles Schwab, Interactive Brokers, or Robinhood. Takes 5-10 minutes online. You'll need your ID and bank info.
Deposit money: Link your bank account and transfer funds. Most brokers allow bank transfers (1-3 days) or wire transfers (same day).
Search for the stock ticker: Every stock has a short code. Apple = AAPL. Vanguard S&P 500 ETF = VOO. Type it in the search bar.
Choose order type and quantity: Market order or limit order? How many shares (or how many dollars worth)? For popular ETFs, a market order during regular hours is fine.
Review and confirm: Double-check the ticker, quantity, and estimated total cost. Then hit "Buy." You now own shares.
That's it. Five steps. The hardest part is step 1 (opening the account). Once that's done, buying a stock takes about 30 seconds. Start with one share of a broad ETF like VOO to get comfortable.
Bid-Ask Spread: Your Hidden Cost
When you look at a stock price, there are actually two prices — and the gap between them costs you money.
Think of buying a used car. The dealer wants $20,000 (the ask). You offer $19,000 (the bid). The $1,000 gap is the "spread." In a busy market with many cars and buyers, the gap shrinks because there's competition. In a sleepy small town, the gap is bigger.
Why It Matters
The spread is an invisible fee you pay every time you trade
If you buy at $100.50 (ask) and immediately sell, you'd only get $99.50 (bid) — instant $1 loss
Popular ETFs like VOO have spreads of $0.01-0.02 — nearly free
Obscure penny stocks can have spreads of 5-10% of the price
Stick to liquid, popular stocks and ETFs where the bid-ask spread is tiny (pennies). This is another reason why VOO and QQQ are great for beginners — the spread is essentially zero.
Settlement: T+1
When you click "Buy," the shares appear in your account instantly — but behind the scenes, the legal transfer of money and ownership takes one more business day.
What This Means in Practice
"T" = the trade date (when you click Buy/Sell)
"+1" = one business day later, the official ownership transfer is complete
Your brokerage handles all of this automatically — you don't need to do anything
The US moved from T+2 to T+1 in May 2024, making settlements faster
For most long-term investors, settlement is invisible. You see the shares in your portfolio right away. The only time T+1 matters is if you sell and want to withdraw the cash — you'll need to wait one business day for the funds to "settle."
T+1 is plumbing you almost never need to think about. Buy your shares, and they're effectively yours immediately. The legal paperwork catches up one day later. Set it and forget it.
Emergency Fund First
Before you invest a single dollar in stocks, there's one non-negotiable step: build an emergency fund.
Why This Is Non-Negotiable
The stock market can drop 30% in a single month (it's happened multiple times)
If you lose your job during a crash and need money for rent, you'll be forced to sell at a loss
An emergency fund means you'll never need to touch your investments during bad times
This is the difference between "temporary paper loss" and "permanent real loss"
The Rules
Save 3-6 months of living expenses in a high-yield savings account or money market fund
Don't invest money you'll need in the next 3-5 years (car, wedding, down payment)
Only invest true surplus — money you could lose 50% of and still sleep fine
The #1 reason beginners lose money in the stock market isn't bad stock picks — it's being forced to sell during a crash because they need the cash. An emergency fund prevents this entirely.
Morgan Housel, The Psychology of Money: "Reasonable is more important than rational." — Having a cash cushion isn't mathematically optimal, but it lets you sleep at night and stay in the game. Choose the approach you can actually stick with.
Module 3 Quiz
Answer all correctly to complete this module. You can retry as many times as you want.
Q1. Which order type guarantees execution but not price?
Market order
Limit order
Stop order
None of the above
Q2. US stock market regular trading hours (Eastern) are:
8:00 AM - 3:00 PM
9:00 AM - 5:00 PM
9:30 AM - 4:00 PM
10:00 AM - 4:30 PM
Q3. The bid-ask spread is:
The commission fee your broker charges
The gap between what buyers offer and what sellers want
The difference between today's high and low price
The annual return on a stock
Q4. T+1 settlement means:
You must hold the stock for at least 1 day before selling
The stock price changes once per day
The trade legally settles 1 business day after you buy
You can only make 1 trade per day
Q5. Before investing, you should first:
Learn technical analysis
Build an emergency fund of 3-6 months expenses
Wait for a market crash to buy low
Find a financial advisor
Q6. Why is pre-market trading riskier?
Lower trading volume
Wider bid-ask spreads
More volatile price swings
All of the above: lower volume, wider spreads, more volatile