"if I owned some shares on both April 9 and May 19...?"
It is only what you own on May 19th that counts, what you owned on Aprl 9th means nothing, but you probably shouldn't waste to much time thinking about it. When the stock give-away was announced, CSJJ PPS was $.20, it is now $.045. It is heading closer to the price you will be paying for it......... $0.00