signal bond

例句：

1. 1.The company issued a new signal bond to raise funds for its expansion plans.
   该公司发行了新的信号债券以筹集资金用于其扩张计划。
2. 2. The government has been issuing signal bonds to stimulate economic growth.
   政府一直在发行信号债券以刺激经济增长。
3. 3.The signal bond market is highly volatile, and investors need to be cautious when buying.
   信号债券市场高度波动，投资者在购买时需要谨慎。