Stock Trading After Hours

When should you sell a part that has significantly increased trade after hours?
After an announcement of the results for after trading hours, an action increases dramatically. Should I try to be the highlight of the trading-hour later (very difficult). Or should wait and wait for stock prices to go even higher when the brand opens again the next day and the time when I'm away? "I can expect the stock price continue to rise, even the next day?
Sell second peaks. Here is where investors are normally po beginners, but also depend on their objectives and strategies
Scottrade – Placing Pre Market and After Hours Stock Orders