No. Do you know how accounting uses the weighted average cost method to compute inventory cost? That applies to stock cost base for tax purposes. What you said is FIFO method (First in First out) that is not the case for tax.
-xjurum(要塞玫瑰);
2008-4-14{150}(#31361@43)
Use the book value provided by your broker as it has been adjusted for tax. It takes time to get the tax base for a stock after many times of trading.