How News Moves Stock Prices: Earnings, Rates, Rumours and Speed

How news moves stock prices comes down to expectations. A share price reflects what investors expect a company to earn and what they will pay for those earnings, so prices react to the surprise in a headline, not to the headline itself. A company can report record profits and still fall. On Oslo Børs, quarterly results, interest rates and the oil price do much of the moving.

Why does news move stock prices at all?

A share is a claim on a company’s future profits. Its price is the market’s current best guess of what those profits are worth today. News matters only when it changes that guess: higher or lower earnings, more or less risk, or a different rate at which the future is discounted.

Eugene Fama’s work on efficient markets made the uncomfortable point that public information gets priced quickly. If a headline is on every screen at once, reading it gives you no edge. Markets are not perfectly efficient, but they are fast.

Oslo Børs, now part of Euronext, adds its own flavour. Energy, shipping and seafood companies carry real weight on the exchange, so prices in Oslo often react to news from far outside Norway: an oil supply cut, a jump in freight rates, a change in salmon prices. Under the market abuse rules that apply across the EU and EEA, listed companies must publish inside information as soon as possible, and Finanstilsynet supervises the market in Norway.

Earnings: why the surprise moves stock prices

Before results, analysts publish forecasts, and their average becomes the consensus. Suppose a company earns 5.00 kroner per share against a consensus of 5.40. That is a miss of about 7.4%, even if 5.00 is the best figure in its history. The share falls because the market had already paid for 5.40.

Guidance often matters more than the quarter just gone. A small miss with a confident outlook can lift a share; a beat with a cautious outlook can sink it. Many companies on Oslo Børs publish results early in the morning, before trading starts, so the verdict shows up in the opening price.

Interest rates: the news that moves everything

When Norges Bank changes its policy rate, it changes the value of every future krone. A profit of 100 kroner expected in ten years is worth about 67.56 kroner today if you discount at 4% a year, and about 55.84 at 6%. That is a fall of roughly 17%. The same 100 kroner expected in two years only loses about 3.7%.

This is why companies whose profits lie far in the future, such as young growth firms, tend to react most to rate news. Banks can react differently, since their lending margins depend on rates. Higher rates also make savings accounts and bonds more attractive next to shares.

Again, expectations decide. If a rate rise is fully expected, the announcement itself may barely register. The real move comes when the decision, or the outlook for the next ones, differs from what was priced in.

Rumours, and why traders buy the rumour and sell the news

When a rumour spreads, early buyers bid the price up. By the time the news is confirmed, much of it is already in the price, and those who bought early sell to take their profit.

A simple illustration. A share trades at 100 kroner. Talk of a merger lifts it to 115 over two weeks. The merger is announced on exactly the expected terms, and the share slips to 110. Anyone who bought at 115 on the day of the “good news” is down about 4.3%.

Two warnings. Many rumours are simply wrong. And trading on information leaked from inside a company is not clever reading of the market; it is a crime. Our guide to where research ends and insider trading begins draws the line clearly.

Reaction speed and volatility: seconds, then weeks

Automated systems read headlines and trade within fractions of a second. By the time a person has read the first line, the first move has happened. Volatility jumps around big news: price swings widen, the gap between buying and selling prices grows, and orders can be filled at worse prices than expected. News released overnight often makes a share open well away from the previous close.

The first move is not always the last. Ball and Brown found in 1968 that prices kept drifting in the direction of an earnings surprise after the announcement, and Bernard and Thomas confirmed this drift two decades later. Markets can overreact too, then partly reverse. Speed is not the same as accuracy.

A calmer way to read a market-moving headline:

1. Ask what was expected: the consensus forecast, or what the price already implied.
2. Measure the surprise: bigger or smaller than expected, and by how much.
3. Decide whether it changes the long-term picture or only one quarter.
4. Watch the first reaction without acting, and note how much volume is behind it.
5. Act only once you can explain the move in a single sentence.

Practising with Ticker TV

Real news rarely shows cause and effect cleanly, because a dozen stories move a share at once. A game can isolate the link. In WallThrone, news on Ticker TV moves prices on the WSX, the game’s fictional exchange, and sometimes it arrives without warning. Prices update every five seconds and every player sees the same market at the same moment, so you also learn what large buyers do to the price for everyone else. The Broker sells tips that are not always right, a fair model of how rumours behave.

Try this: when a story breaks, write down the direction you expect and why, then check the chart five minutes later. After a few dozen headlines you will know whether you read news well, or simply react to it. The companies are fictional and the prices come from the game’s own model, so treat it as training for judgement, not as a forecast of any real share. The same habit pays off when you study the psychology behind crowd reactions.

Frequently asked questions

WallThrone is a game with play money and fictional companies on its own exchange; it is neither a broker nor a source of market news. This article is general education and not financial advice.