Valero Energy Corp. (VRE.US) stock price is influenced by several factors: Crude Oil Prices: As a refiner, Valero's profitability is closely tied to the price of crude oil, its primary input. Lower crude oil prices generally benefit Valero by reducing input costs.

Refining Margins: The difference between the price of refined products (gasoline, diesel, jet fuel) and the cost of crude oil significantly impacts Valero's earnings. Wider refining margins lead to higher profits.

Demand for Refined Products: Consumer demand for gasoline, diesel, and jet fuel affects prices and, therefore, Valero's revenue. Economic growth, seasonality, and driving habits influence demand.

Inventory Levels: High inventory levels of crude oil and refined products can put downward pressure on prices, impacting Valero's profitability.

Geopolitical Events: Global events, such as political instability in oil-producing regions or international conflicts, can disrupt supply chains and affect both crude oil prices and refining margins.

Regulatory Environment: Environmental regulations and government policies regarding fuel standards and emissions can impact Valero's operating costs and investment decisions.

Economic Conditions: Overall economic growth or recessionary pressures impact demand for refined products and, consequently, Valero's financial performance.

Company-Specific Factors: Valero's operational efficiency, refining capacity, and strategic decisions (such as acquisitions or divestitures) also influence its stock price.

Investor Sentiment: General market sentiment and investor perception of the energy sector can drive buying or selling pressure on Valero's stock.

Renewable Fuel Standards (RFS): Government mandates requiring refiners to blend renewable fuels into gasoline can create compliance costs for Valero, affecting profitability.