Several factors contribute to determining the number of held shares for a particular stock. Firstly, investor demand plays a significant role. If a company's stock is perceived as attractive, investors may acquire and hold more shares, increasing the overall number of held shares. This demand can be influenced by factors such as the company's financial performance, growth prospects, industry trends, and investor sentiment.

Institutional investors also have a considerable impact on the number of held shares. Large investment firms, mutual funds, and pension funds often hold significant positions in stocks. Their buying or selling activity can significantly affect the number of held shares.

Furthermore, stock buybacks or share repurchase programs initiated by the company can reduce the number of held shares. When a company buys back its own shares, the total outstanding shares decrease, leading to a higher percentage of held shares.

Additionally, factors like dividend reinvestment programs, stock options granted to employees, and restricted stock awards can influence the number of held shares.

Overall, the number of held shares is influenced by a combination of investor demand, institutional holdings, share repurchases, and various corporate actions, all of which can fluctuate over time and impact the stock's liquidity and market dynamics.