what do 接盘 and 接盘侠 mean?
The person who buys the company shares you are selling is the 接盘 

Metaphorically, 接盘侠 is a man, 侠, who 接盘s 

A is a loose woman, B and others are her lovers, maybe she gets pregnant, B does not want her, so she looks for C or D or E, seems to love him, asks if he wants to marry her, has sex with him then says, "OMG, I'm pregnant!"

接盘侠 is 喜当爹

喜当爹：a man who is not so interesting, likes a woman, the woman is aloof, but eventually comes back to him, because she is pregnant. She marries him because her socially and otherwise more attractive boyfriend doesn't want her, or can't, for family reasons, have her.