Most Powerful Force Impacting Stock Prices The change in a company's future earnings potential, as reflected in earnings estimate revisions, has proven to be strongly correlated with the near-term price movement of its stock. That's partly because of the influence of institutional investors that use earnings and earnings estimates for calculating the fair value of a company's shares. An increase or decrease in earnings estimates in their valuation models simply results in higher or lower fair value for a stock, and institutional investors typically buy or sell it. Their transaction of large amounts of shares then leads to price movement for the stock. Fundamentally speaking, rising earnings estimates and the consequent rating upgrade for Builders FirstSource imply an improvement in the company's underlying business. Investors should show their appreciation for this improving business trend by pushing the stock higher.