1. Management cost: Holding spot needs to pay management costs such as warehousing and insurance, and futures trading can avoid these costs. Therefore, the spot price will gradually approach the final price before it expires.

2. Market expectation: Market participants' prediction of future market trends is also an important factor affecting the convergence of spot and ending prices. If the market generally believes that a commodity will be oversupplied or demand will decline in the future, then the spot price may be lower than the final price; On the contrary, it may be higher than the final price.

In short, the spot and end-of-term spreads are uncertain to some extent, but they tend to converge with the passage of time and changes in the market.