Open futures refer to long positions established by investors for speculative futures. As long as futures prices fall, investors will lose money. Therefore, the empty orders of futures bulls will lead to a decline in futures prices.

On the one hand, in the futures market, when long futures positions are opened (that is, when futures prices rise), investors can take advantage of the opportunity of buying at a low price and selling at a high price to realize the return on investment. At this time, futures prices will rise, but when futures prices rise beyond investors' expectations, investors will generally choose to lighten their positions cautiously, which will lead to a decline in futures prices.

On the other hand, after long positions in futures, investors may see the future trend from the futures price trend, and reduce their positions according to this trend, which will lead to the decline of futures prices. For example, investors may think that futures prices will fall in the future, so they start to lighten their positions, which will lead to the decline of futures prices, which will lead to more futures opening and falling.

In addition, the opening of futures bulls may also be affected by the macroeconomic situation in the market. For example, the depression of financial market and the slowdown of economic development may lead investors to reduce their positions cautiously, which in turn will lead to the decline of futures prices, thus making futures open more. In short, the long position of futures may be due to the inaccurate expectations of investors on the trend of futures prices, or the influence of macroeconomic conditions, which leads to the cautious lightening of investors' positions and the decline of futures prices, thus making futures open more.