What Moves Stock Prices?

The Long Run: Fundamentals

Over years, a stock follows the business. Rising earnings, a growing economy and falling interest rates tend to lift prices; the reverse tends to weigh on them. This is the weighing machine: given enough time, real value wins out. A company that steadily grows its profits will, over the long run, see its share price grow with it, regardless of the noise along the way.

Interest rates deserve special mention, because they affect every stock at once. A share is ultimately worth the value of its future profits, and higher rates make those future profits worth less in today’s money, while also making safer alternatives like bonds more attractive. That is why a single decision by a central bank can move the entire market: it changes the yardstick against which all those future earnings are measured. Over the long run, then, the two great fundamental levers are how fast a company’s earnings grow and the level of interest rates used to value them.

The Short Run: Supply, Demand and Sentiment

Over days and weeks, the same stock can swing on mood alone. At the most basic level, price is set by supply and demand: if more people want to buy than sell, the price rises, and vice versa, and that balance is driven largely by sentiment. News lands differently depending on how the crowd feels; a good earnings report can be sold off, a bad one bought. Benjamin Graham’s line captures it: in the short run the market is a voting machine, and the votes are emotional. That gap between value and price is investor sentiment, and it is what drives most short-term moves.

The Specific Catalysts

On any given day, a stock moves on a recognisable set of catalysts. Earnings reports are the biggest, capable of repricing a stock in milliseconds when they beat or miss expectations. Analyst upgrades and downgrades shift demand. Decisions by the Federal Reserve on interest rates ripple through every valuation. Economic data, like inflation and jobs reports, moves the whole market at once. And company-specific news, a new product, a lawsuit, a merger, a scandal, hits individual names. Underneath all of these, the wider market’s mood acts as an amplifier: the same piece of news can spark a rally in a greedy market and a sell-off in a fearful one.

Why Expectations Beat Facts

The most confusing thing about short-term moves is that prices react to surprises relative to expectations, not to the raw facts. A company can post record profits and fall, because the market expected even more, and a struggling one can rally on losing less than feared. This is because the market is forward-looking and "prices in" what it already anticipates, so only the gap between reality and expectation moves the price. It is why "buy the rumour, sell the news" is a market saying: by the time good news is official, it is often already in the price, and the buyers who chased the rumour sell to the latecomers. Understanding that the bar is the expectation, not the fact, explains most of the otherwise baffling reactions to news.

How Well Does Sentiment Explain Prices?

Well for today, poorly for tomorrow. CFGI data mirrors same-day market direction 79% of the time, but its agreement with the next day falls to 49%, close to a coin flip. So sentiment tells you where the crowd stands now, not where price goes next. The practical takeaway is to match your lens to your horizon: if you are investing for years, focus on the fundamentals that the weighing machine ultimately rewards, and treat the daily mood as noise; if you are trading over days, the sentiment and the expectations game matter far more than any long-run valuation. See the equity mood on the Stock Fear and Greed Index.