Learn the stock market › Why does a stock move? › Lesson 2 of 9
Why do stocks go up and down?
Boliden over the last year
Boliden moved at least 4% on 35 trading days in the last year. These are the three largest of the moves where our review of that day says what the move came after.
| Day | Move | What our review of the day said |
|---|---|---|
| Mar 26, 2026 | −19.9% | Boliden plunged after Garpenberg mine damage on Thursday. |
| Jul 21, 2026 | −5.7% | Boliden fell after its second-quarter report on Tuesday. |
| Aug 21, 2026 | +4.9% | Boliden rose after Drillcon extended its Zinkgruvan contract on the trading day. |
The numbers come from closing prices, and the sentence is the one written for that day. A move coming after an event shows they fall together in time. It does not prove the event alone explains the whole move.
Three kinds of cause
Something happens in the company. A report, a big order, an accident, an acquisition. It changes what the company is expected to earn and can move the price the same day.
Something happens around the company. The whole market falls, interest rates change, the currency moves or a whole sector gets bad news. The stock moves although nothing happened at that company. See the lesson on the market, the one on rates and the one on sectors.
Nothing you can see. Often there is no news to point at. The last lesson shows how common that is. What happened after the very largest falls is in the study of one-day falls.
Test yourself
A stock rises 5% in a day with no news from the company. What can you say for certain?
What happened on the other days? Why did Boliden move?