I've noticed that my brokerage (Wells Fargo) uses a different system to calculate my profits and losses, instead of the mental accounting I follow.
E.g.,
I buy 100 shares of stock A in July 2014 at $200 each.
Then, I buy 100 more shares of stock A in August 2014 at $100 each.
Then in September 2014 I sell 100 shares of stock A at $150 each.
Mentally, I've broken even on these shares (if I use the average cost of the shares), or made a loss of $50 (if I use the cost of the first batch of shares).
However, my brokerage reports this as a profit of $50 (it's using the cost of the last batch for reference).
Before my tax statement shows up at the end of the year, is there anything I can do to make my brokerage change how it calculates profits and losses? There must be various accounting standards (FIFO - first in first out, LIFO - last in first out, etc.)... and perhaps I can choose which one I want to follow?