That's simple. The outstanding shares are reduced, but in most cases, the AUTHRORIZED SHARES are NOT reduced. So, the company issues NEW shares right after the r/s. While your shares need to be sent by your broker to the TA for replacement shares, which takes time, YOU can't trade. However, the company has plenty of NEW shares to dump immediately, which causes the PPS to plummet, before you can sell yours, thus creating "shareholder value". NOT!
News 
Market Data 
Discover 
