The open contract of stock index futures contract refers to the sum of all open contracts in the futures market, usually in sheets. Open position contract is one of the important indicators to measure market liquidity and trading activity, which can help investors understand the market demand and interest for specific contracts.

The change of positions can reflect the comparison of long and short positions in the market. When the open position contract increases, it may mean that the market demand for the contract increases, which may be due to the growing differences between investors who are bullish or bearish on the market outlook. On the contrary, when the positions are reduced, it may mean that the market demand for the contract is reduced, which may be because investors tend to agree on the market outlook, or because some investors close their positions and leave.

It should be noted that the change of positions is not the only factor that determines the market trend, and investors need to make a comprehensive analysis based on other indicators and market information. In addition, excessive attention to positions may lead to excessive speculation and increase trading risks. Therefore, investors should be rational and cautious when analyzing their positions.