Market capitalization, the total value of a company's outstanding shares, is influenced by several factors that can cause it to change. The primary factor is the company's stock price, which fluctuates based on supply and demand in the stock market. When more investors buy a company's shares, the stock price rises, increasing its market capitalization. Conversely, if more investors sell their shares, the stock price falls, decreasing the market capitalization.

Company performance and financial health significantly impact market capitalization. Positive earnings reports, revenue growth, and successful product launches can boost investor confidence, leading to higher stock prices. Conversely, poor financial performance, declining sales, or failed projects can result in lower stock prices.

External economic conditions also play a crucial role. Economic growth, interest rates, and inflation influence investor sentiment and market trends. For example, a strong economy generally boosts stock markets, increasing market capitalizations, while economic downturns can have the opposite effect.

Market sentiment and investor perceptions can cause fluctuations as well. News, rumors, or changes in industry trends can affect investor behavior. Regulatory changes, political events, and global crises can create uncertainty, impacting stock prices and market capitalizations.

Lastly, changes in the number of shares outstanding, due to actions like stock splits, buybacks, or secondary offerings, directly affect market capitalization. These corporate actions alter the number of shares available, thereby impacting the total value of the company's shares in the market.