During a stock market breakdown, the movement of stocks can vary depending on a variety of factors. Typically, a breakdown is characterized by a significant and sustained decline in stock prices, often accompanied by high levels of volatility and trading volume.

In this environment, investors may be more likely to sell their shares, which can put downward pressure on stock prices. However, the magnitude and duration of the decline can vary depending on a range of factors, including the underlying causes of the breakdown, the overall health of the economy, and the actions of policymakers and market participants.

During a breakdown, certain sectors or industries may be particularly vulnerable to declines, while others may be relatively insulated. For example, technology companies may be more sensitive to changes in investor sentiment and market conditions, while defensive sectors such as utilities and consumer staples may be less affected.

Overall, the movement of stocks during a breakdown can be unpredictable and can vary depending on a range of factors. It's important for investors to carefully monitor market conditions, diversify their portfolios, and be prepared to adjust their strategies as needed in response to changing market conditions.