Markets

Industry · Markets

Stock market news as it moves: earnings, index swings, sector shifts, and what is driving the S&P 500, Nasdaq, and Dow.

Latest Markets

Big Tech Finance Startups Markets

About Markets

What an index is, and what it is not

A stock index is a defined basket of companies with a rule for weighting them, maintained by a committee or a formula. Most major indices weight by market value, so the largest companies dominate the number and a broad index can rise while most of its members fall. Membership is decided by a set of criteria, and inclusion or removal moves a share price on its own because funds tracking the index must buy or sell accordingly. Reporting that treats an index as a summary of the economy is therefore reading it as something it was never designed to be.

Why prices move

A share price reflects collective expectations about a company's future cash flows and the risk attached to them, discounted back to a value today. Two consequences follow that explain most confusing market news. First, prices respond to surprises rather than to results, so a company reporting record profit can fall if the profit was smaller than expected. Second, interest rates matter enormously, because a higher rate makes future earnings worth less in present terms, which is why central bank decisions move markets that have nothing obvious to do with banking.

The earnings calendar and who is speaking

Listed companies report on a quarterly cycle, publishing audited figures alongside management commentary and, often, guidance about expected future performance. Analysts publish forecasts, and the consensus of those forecasts becomes the benchmark a result is judged against. It is worth separating the three voices in any earnings story: the audited numbers, which are constrained by accounting standards; management's characterization of them, which is not; and analyst reaction, which comes from people whose firms may also do business with the company.

Who is doing the trading

The picture of markets as individuals choosing shares is largely obsolete. Most volume comes from institutions, and a very large share of invested money sits in funds that simply track an index rather than selecting anything, which means enormous flows are driven by membership rules rather than by opinion about a company. Algorithmic and high frequency trading supplies much of the moment-to-moment liquidity. Derivatives let participants take positions far larger than the money committed, and activity in options can move the underlying shares through the hedging it forces, which is why a price sometimes moves for reasons that have nothing to do with the company at all.