ForecastingStocks

Commodity prices are ultimately a tug-of-war between supply and demand, but several specific forces push on each side.

Supply-side drivers

Weather and harvests — a drought in Brazil's coffee belt or a frost in the cane fields can cut supply and spike prices. Agricultural commodities are intensely weather-sensitive.
Geopolitics — wars, sanctions and OPEC decisions can choke or release oil supply almost overnight.
Production costs and capacity — the cost to pull a barrel of oil or an ounce of gold out of the ground sets a rough floor; new mines or wells add supply slowly.
Inventories and stockpiles — published storage levels (e.g. US crude inventories) signal whether the market is tight or oversupplied.

Demand-side drivers

Economic growth — industrial metals like copper rise when factories and construction are booming; copper is so cyclical it is nicknamed Dr. Copper for its read on the economy.
The US dollar — most commodities are priced in dollars, so a stronger dollar tends to push commodity prices down (they become more expensive in other currencies) and a weaker dollar lifts them.
Inflation expectations — commodities are a classic inflation hedge, so rising inflation expectations can lift demand from investors.
Substitution and technology — cheaper natural gas can displace coal; electric vehicles raise demand for copper and lithium while denting oil.

The Brazil angle

Because Brazil exports so heavily, its harvests and its currency matter globally. A weak real makes Brazilian soybeans and coffee cheaper on world markets, boosting export volumes; a record safra (harvest) can move global prices. Watching Brazil is part of watching the soft-commodity complex.

Reading these drivers is the analytical core of commodity investing — far more than chart patterns alone.