Beta
How much a stock has tended to move relative to the overall market — above 1 means historically more volatile than the market, below 1 means less.
What it means
Beta measures how much a stock's price has historically moved relative to a broad market benchmark (typically the S&P 500). A beta of 1.0 means the stock has tended to move in line with the market; a beta of 1.5 means it's tended to move about 50% more than the market in either direction — bigger gains on up days, bigger losses on down days; a beta below 1.0 means historically smaller moves than the market, and a negative beta (rare) means the stock has tended to move opposite the market. Beta is calculated from historical price data, which makes it a backward-looking statistical measure of past volatility and correlation, not a prediction of how a stock will behave going forward.
How MarketWall calculates it
MarketWall reports beta from each stock's weekly Yahoo Finance fundamentals sync, the same beta figure shown on every stock page's Fundamentals card. See the Data Sources & Methodology page for the full sync schedule.
How it's typically used
Beta is a portfolio-construction tool as much as a stock-picking one. A high-beta stock amplifies whatever the broader market does — a portfolio full of high-beta names will generally outperform in a rising market and underperform more sharply in a falling one, while a portfolio weighted toward low-beta stocks tends to be steadier in both directions. Neither is inherently better; it depends entirely on what an investor is trying to achieve and how much volatility they're comfortable holding. Beta says nothing about a company's underlying quality, its valuation, or its growth prospects — a high-beta stock isn't necessarily riskier in the sense of being a worse business, just more volatile in price. It's also worth remembering what beta doesn't capture: it's calculated over a specific historical lookback window, so a stock's beta can shift meaningfully as its business changes (a company diversifying into new markets, for instance, may see its beta drift), and a short, unusual period in the data (a single crisis, a stock-specific event) can skew the number. Comparing beta across companies in the same sector is generally more useful than comparing it across sectors — cyclical industries (retail, industrials, small-cap tech) structurally run higher betas than defensive ones (utilities, consumer staples, healthcare), so a "high" beta in a defensive sector means something different from the same number in a cyclical one.
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FAQ
What does a beta of 1.0 mean?
It means the stock has historically moved roughly in line with the broader market — similar percentage gains and losses on average.
Is a high-beta stock always riskier?
It's more volatile in price, which is one kind of risk, but beta says nothing about the company's fundamentals, valuation, or business quality — a high-beta stock isn't automatically a worse company.
Can a stock have a negative beta?
Yes, though it's uncommon — it means the stock has historically tended to move opposite the broader market, which some investors specifically seek out for diversification.
What market benchmark does beta compare against?
The standard convention (and what Yahoo Finance's figure, which MarketWall reports, uses) is the S&P 500.
See more signals in the interactive walkthrough, read the full Data Sources & Methodology page, or explore it live on a real chart — AAPL or BTC.