speculative grade

例句：

1. 1. The company's speculative grade is a key factor in its investment strategy.
   公司的投机性评级是其投资策略的关键因素。
2. 2.The speculative grade of the stock has increased significantly since last year.
   该股票的投机性评级自去年以来显著提高。
3. 3.The speculative grade of the project is considered to be high, indicating that it may not be as successful as expected.
   该项目的投机性评级被认为较高，表明其可能不如预期成功。