how is taxes calculated for purchasing stocks this way ?

[aim-high]

I understand we have short term capital gain tax and long term. short term if you buy and sell stock within a year and long term tax if I buy the stock, keep it for more than a year and then sell it.
Here is my case
Bought x stocks of a company on 6/30/2009
Bought y more stocks of the company on 1/30/2010
If I sell x stocks on 12/01/2010, for those x stocks will I have to pay long term capital gain tax because I have held if for more than a year ?

Secondly, what if I sell all my stocks on 12/01/2010. will I pay short term tax on x stocks and long term tax on y stocks ?

[disneysteve]

The assumption is FIFO - First In, First Out. So if you bought 100 shares 6/09 and 100 shares 1/10 and then sell 100 shares, they assume you are selling the first 100.

If you sell it all, yes, you will be taxed differently on the 2 lots.

[jIM_Ohio]

all info so far is correct- when you sell, you can specify which shares you are selling BEFORE you complete the transaction. If you do this, keep good records.

[disneysteve]

all info so far is correct- when you sell, you can specify which shares you are selling BEFORE you complete the transaction. If you do this, keep good records.

Yes. In case you are wondering why you would want to specify, there are a few reasons.

One reason is the one we've just discussed. You want to sell the shares with the long term capital gain and lower tax rate.

Another reason could be that you are trying to lock in a capital loss to offset other gains. In that case, you might want to sell the shares you bought at the highest price.