If shares are purchased on multiple transactions, several cost bases will be generated. When they are sold off, you need to consider the original costs to determine profit/loss generated. Your gain or loss depends on the way you calculate cost basis. The common ways of calculating cost basis include FIFO (First-In-First-Out), LIFO (Last-In-First-Out), Average Cost.
Our MooMoo App currently displays cost basis for the security using average cost method. However, FIFO method is used to calculate cost basis for tax reporting purpose.
For example, you purchase 100 shares of A on 3rd Oct 2019 $8 per share and another 100 shares of A on 10th Oct 2019, at $10 per share. You then sell, on 16th Oct 2019, 100 shares of A for $12 per share.
By applying FIFO, the sale of the 100 shares on 16th Oct is considered as made against the batch purchased on 3rd OCT, total gain will be (12 - 8)*100 = $400
By applying LIFO, the sale of the 100 shares on 10th Oct is considered as made against the batch purchased on 3rd OCT, total gain will be (12 - 10)*100 = $200
By applying average cost method, cost of each share is averaged out as (8 + 10) / 2 = $9/share, the sale of 100 shares will result in a capital gain of (12 – 9)*100 = $300
Moomoo Inc. and its affiliates do not provide tax advice. Please consult a qualified tax advisor for your personal financial planning and tax situations.