Cost Basis Calculator (FIFO/Average)

Why Cost Basis Tracking Matters on BODIVA

Angola’s Imposto sobre a Aplicacao de Capitais (IAC) levies a 10% tax on capital gains realized from the sale of listed securities on BODIVA (Bolsa de Divida e Valores de Angola). The taxable gain is calculated as the difference between the sale proceeds and the adjusted cost basis – meaning that accurate tracking of purchase prices, brokerage commissions, and any additional transaction fees directly determines your tax liability. Overstating your basis reduces reported gains (and risks an AGT audit); understating it means paying more tax than legally required.

What This Tool Does

The Cost Basis Calculator computes your adjusted cost per share after factoring in brokerage fees, then compares this adjusted basis against the current market price to determine your unrealized gain or loss and the estimated capital gains tax due upon sale. The tool supports both the FIFO (First In, First Out) method and the weighted average cost method – the two approaches most commonly accepted under Angolan tax guidelines for securities portfolio accounting.

How to Use It

1. Enter the purchase price per share in Kwanza. For example, Kz 1,000 for a BODIVA-listed equity.
2. Enter the number of shares acquired in the transaction.
3. Set the brokerage fee percentage – BODIVA-authorized brokers (sociedades corretoras) typically charge between 0.3% and 1.0% of the transaction value, depending on the size and broker.
4. Enter the current market price per share to calculate unrealized gains.
5. Click Calculate to view your total cost including fees, adjusted cost per share, unrealized gain/loss in both absolute and percentage terms, and the estimated 10% IAC capital gains tax.

Worked Example: BAI Equity Position

An investor purchased 500 shares of a BODIVA-listed bank equity at Kz 1,000 per share through a broker charging 0.5%. The current market price is Kz 1,250:

At the current USD/AOA rate of ~914.60, the net after-tax gain of Kz 110,250 equals approximately $120.55. However, if this position was held for six months and the Kwanza depreciated 5% during the holding period, the USD-equivalent gain would be further reduced – a consideration that matters for investors who measure returns in hard currency.

Multiple Purchase Lots: FIFO vs. Average Cost

For investors who build positions over time (a common approach given BODIVA’s thin liquidity), tracking multiple purchase lots is essential. Consider an investor who bought shares in two tranches:

• FIFO method (selling 200 shares): cost basis = first 200 from Lot 1 at Kz 903.00/share adjusted = Kz 180,600
• Average cost method (selling 200 shares): average cost = Kz 492,450 / 500 = Kz 984.90/share, so cost basis = Kz 196,980

The method chosen can produce materially different tax outcomes, particularly when share prices have moved significantly between lots.

BODIVA Trading Cost Reference

For comprehensive position analysis, use the DCA Calculator to model systematic purchases over time, the Watchlist to monitor current prices on your holdings, and the Real Return Calculator to assess whether your equity gains outpace inflation (15.7% YoY per INE, December 2025) after tax. The Portfolio Builder helps position sizing across multiple BODIVA holdings.