（1） Supply and demand of corn
1. Corn supply
From the production situation over the years, in the international corn market, the output of the United States accounts for more than 40%, that of China accounts for nearly 20%, and that of South America accounts for about 10%. It has become the main production area of corn in the world. Its output and supply have a great impact on the international market, especially the output of the United States has become the most important factor affecting international supply. The proportion of output in other countries and regions is low, which has little impact on the international market.
Relative to soybeans, etc agriculture products China's corn production is relatively independent, with low annual imports and relatively stable exports. The annual domestic output has become the main factor affecting domestic supply. Generally speaking, domestic corn began to come into the market in succession at the end of October, when the spot price of corn fell. In May and June of the coming year, corn began to be in short supply, and the price began to rise. In July and August, the price reached its peak.
2. Demand for corn
The United States and China are both major producers and consumers of corn. Countries that consume more corn include the European Union, Japan, Brazil, Mexico and other countries. Changes in consumption demand in these countries have a greater impact on corn prices. In particular, in recent years, the rapid development of corn deep processing industry in major consumer countries has greatly promoted the increase of corn consumption demand.
From the domestic situation, corn consumption mainly comes from feed and processing industry. Due to the impact of the international market and epidemic situation, the animal husbandry has been initially stable over the years, which has directly affected the demand for feed, and then the demand for corn, thus affecting the price trend of corn. In recent years, the development of corn deep processing has increased the demand for corn and tightened the supply, which has become the direct driving force for its price rise.
3. Impact of corn stocks
In a certain period, the inventory level of a commodity directly reflects the changes in the supply and demand of the commodity, and is an internal reflection of the supply and demand pattern of the commodity. Therefore, studying the changes of corn inventory is helpful to understand the operating trend of corn prices. Generally, when the inventory level increases, the price of corn drops; When the inventory level decreases, the corn price rises, and there is a negative correlation between the carry over inventory level and the corn price.
4. Price of related goods
The food varieties most closely related to corn include feed wheat and feed rice. The price practice over the years shows that the above grain varieties have a certain substitution role in the consumption process. For example, the normal price comparison relationship between feed wheat and corn is about 0.9:1.0. If the price comparison relationship between the two exceeds this level and the range is large, the substitution of the two commodities in use will occur. Therefore, the price of wheat and rice has become a very important factor affecting the price trend of corn.
In addition, since corn is mainly used for feed production at this stage, the price change of soybean meal also used for feed production will affect the price of corn to a large extent. Although the two cannot replace each other, in the current situation of abundant domestic soybean meal supply, the rise and fall of soybean meal price is often a direct reflection of the increase and decrease of market feed output and demand, and the change of corn price will be affected by the change of feed demand.
（2） Climate Impact
As an agricultural product, both spot price and futures price of corn will be affected by weather factors. During sowing and growth, the improvement of weather conditions will change the yield of corn from reduced to increased, and lead to changes in the psychological expectations of supply and demand, which will bring downward pressure on corn prices. On the contrary, the price of corn will induce the expectation of tight supply due to long-term drought or other adverse weather factors, and generate the impetus to push up the price.
As the United States is the largest corn producer and exporter in the world, not only the change of domestic weather in China will have an impact on the change of futures prices in China, but also the change of weather in the United States will have a greater impact on the price of corn in China, and the change of weather in other major producers such as South America will also have a certain impact on the price of corn in China. Since the United States and China are at the same latitude, the planting and growth periods of corn in both countries are basically the same. Every April to September is the time to hype the corn planting area and weather (mainly reflecting the growth status of crops) in both countries. The weather conditions in South American corn producing areas from October to March of the next year have become one of the factors concerned by the futures market. Generally, the price of corn starts to decline when the supply reaches its peak in the harvest period, and reaches its peak in the spring and early summer when the supply is scarce and the yield of new crops is uncertain. In the middle to late summer, the yield of new crops will gradually become clear, but it is also the most critical period affected by the weather. Therefore, we should pay serious attention to it. The price of corn will fall before the harvest. The response of corn prices to weather changes ultimately depends on the overall supply and demand of the market.
（3） Business cycle
The world economy is constantly developing in the cyclical alternation of prosperity and recession. The economic cycle is an inevitable economic fluctuation in modern economic society and one of the basic characteristics of modern economy. In the economic cycle, fluctuations in economic activities occur in almost all economic sectors. Therefore, the economic cycle is the fluctuation of the overall economy rather than the local economy. The basic indicator to measure the overall economic situation is the national income, and the economic cycle is also manifested as the fluctuation of the national income, resulting in fluctuations in output, employment, price level, interest rate, etc. The economic cycle appears repeatedly in the operation of the economy, generally consisting of four stages: recovery, prosperity, recession and depression. As a result, the price of corn will fluctuate accordingly. From a macro perspective, the economic cycle is one of the most important factors.
（4） Exchange rate of currency
Whether measured in RMB or US dollar, the fluctuation of the real currency value of the currency will inevitably affect the spot price of corn, as well as the futures price. Because there is a certain linkage between financial assets and commodity futures, in general, when the currency depreciates, the price of corn futures will rise accordingly; When the currency appreciates, futures prices will fall. Therefore, the currency exchange rate is another important factor besides the main factors that determine the price of corn futures, such as supply, demand and economic cycle. From the relationship between the trend of CBOT corn and other commodity futures and the trend of the US dollar since 2002, we can see that the depreciation of the US dollar is one of the main factors driving the rise of commodity futures prices.
（5） Impact of relevant national policies
The state's grain industrial policies have always influenced or even controlled the corn market and corn prices. Since the mid-1980s, China has been committed to the market-oriented reform of grain. From 1985 to 1997, the "contract ordering, state ordering and price dual track system", and 1998, the "three policies and one reform", In 2001, the policy of "opening up sales areas, protecting areas, taking charge of provincial governors, and strengthening regulation" has fully opened up the grain purchase market so as to realize the marketization of grain purchase and sale and the diversification of market players. After years of reform, China's corn market has basically reached a fully market-oriented operation, and corn prices have basically fully reflected market supply and demand. However, relevant industrial policies, import and export policies, reserve policies, and monetary policies will still have an important impact on the corn market and its price trend, which needs attention.
（6） Other factors
In addition to the impact of the above five main aspects, during the planting and growth of corn, attention should also be paid to the impact of domestic economic prosperity, political situation, military action and some emergencies on the price trend of corn.
(Source: Dalian Commodity Exchange (Weibo) )
