Compute stock trading profit and loss.
买入额 = 买入价×股数、卖出额 = 卖出价×股数;佣金按成交额比例收取且不低于最低佣金;印花税仅卖出单边征收,过户费按成交额比例双向收取。
| Item | Formula / Rule | Source / Standard |
|---|---|---|
| Profit and loss | Net P&L = (sell price − buy price) × shares − buy costs − sell costs − stamp duty | CFA Institute 2024, GIPS 2020, Ch. 2 |
| Return measure | Return = net P&L / (buy price × shares + buy costs), the denominator being capital actually deployed | CFA Institute 2024, GIPS 2020, Ch. 2 |
| Cost drag | Round-trip costs and taxes raise the break-even gain materially, most visibly in short-term trading | CFA Institute 2024, GIPS 2020, Ch. 2 |