<p>Beta, in finance, is a measure of an asset's sensitivity to market movements. It quantifies the asset's systematic risk, indicating how much its returns vary compared to the market as a whole.</p>

<h2>How It Works</h2>
<p>Beta is calculated using the following formula:</p>
<p><strong>Beta = Covariance (Asset Returns, Market Returns) / Variance (Market Returns)</strong></p>
<p>Where:</p>
<ul>
  <li>Covariance measures how two assets move together</li>
  <li>Variance measures the dispersion of market returns</li>
</ul>
<p>If the beta is 1, the asset moves with the market. If it's higher than 1, the asset is more volatile than the market. If it's lower than 1, the asset is less volatile.</p>

<h2>Why It Matters</h2>
<p>Beta is crucial for portfolio management. It helps investors understand the risk they're taking on and make informed decisions. For example, if an investor wants a portfolio with less risk than the market, they would choose assets with betas less than 1.</p>