Open-market repurchases differ from the first three described with respect to the credibility of their signaling power.
就其所传达的信号的可信度而言,公开市场（股票）回购与前面三种是不同的.
A firm offers to buy a specified fraction of shares within a given time period.
一家公司在给定时间内出价购买一部分股票
offer 主动提出,出价