Don't chase a stock. Yes Xin could go straight up from here. But more likely is that it will come back down and you can buy more shares. You haven't said how many shares you have or what % Xin is of your portfolio. You shouldn't put more than 10% of your portfolio in ANY stock.
i only bought 500 at 3.05 still kicking myself in the #$%$ for that one also sold sprint when it ws at $4 and clwr at 2.30 i make my profits by atleast 20% i guess well I'm not greedy i stop while im ahead but when i stop it seems they keep soaring