Start with understanding
Investing Basics
Understand a little. Practice once. Write your own plan. Each lesson explains an idea with an example, then asks you to answer a question and write a short reason before reading the explanation. Gather your thoughts as you learn, then follow the prompts to write your own learning or investment plan.
Read and practice first. Sign in to save personal plans and records.
Sign in to save progressAbout 5 minutes
03 · What a quote tells you
What you’ll learn
Before interpreting a quote, check which price it is being compared with.
A percentage change compares two prices. The starting price is called the baseline, often the previous regular session’s closing price. It may be different from what you paid, so the displayed change may not match your own gain or loss.
Also check the quote’s time, currency, source, and whether it comes from regular or extended trading hours. Quotes may be delayed and do not guarantee an execution price. Explaining why the price moved requires more evidence than the price change alone.
See it in an example
Suppose the baseline is 100 and the latest price is 98. The difference is −2, so −2 ÷ 100 × 100% gives a 2% decline. If you actually bought at 90, your own result starts from 90 and also needs to account for costs, rather than using the displayed −2%.
Percentage change
- Plain meaning
- Percentage change tells you how much a price rose or fell relative to a baseline. Quote pages often use the previous trading day’s close, but always check the stated baseline and quote time.
- See it in an example
- If the previous close was 100 and the current quote is 102, the change is (102 − 100) ÷ 100 = 2%. If you bought at 110, today’s 2% rise does not mean your holding is profitable.
- When would I use this?
- For a quote, check baseline, currency, and time. For your own return, also examine purchase cost, fees, and dividends.
- Common misconception
- A percentage change describes the size of a move. It does not by itself explain the cause or measure your account return.
Trading volume
- Plain meaning
- Trading volume is the quantity of securities traded during a period, commonly measured in shares or market-specific lots. It describes trading activity, not the money value of those trades.
- See it in an example
- If 1,000 shares trade in the morning and 2,000 in the afternoon, daily volume is 3,000 shares. Each trade has a buyer and a seller; it is not counted twice just because both participated.
- When would I use this?
- Before comparing days, check matching units and sessions. Half a day’s trading cannot be directly compared with a full day without accounting for the difference.
- Common misconception
- Higher volume does not guarantee a rising price. Heavy trading can accompany a decline too.
Use what you just learned to answer a question
Choose the answer you think fits and write a short reason in your own words. Then submit to see the answer and explanation and check your understanding.
Try this for yourself
Next time you read a quote, identify the price, comparison baseline, and update time. If one is missing, record it as something to check.
04 · Understand risk in amounts
Explore further
Learning and research support; no personal trade instructions or guaranteed returns. · Version 2026-09-13.1