Corporate actions are events initiated by listed companies that affect their share structure, ownership, or value. In Nigeria, the most common are cash dividends, bonus share issues, rights offerings, and stock splits. Bonus issues are particularly frequent on the NGX and often misunderstood by retail investors. Tracking these accurately is essential for calculating correct historical returns.
Cash dividends are the most straightforward: the company pays you money per share. But Nigeria's equity market has some distinctive patterns. Bonus share issues are far more common here than in developed markets. A 1-for-5 bonus means you get one new share for every five you hold. The share price adjusts downward proportionally, so you're not richer the day after. You just own more shares at a lower price.
Why do Nigerian companies love bonus issues? Partly because of a historical preference for low nominal share prices, which retail investors perceive as "affordable." Partly as a signal of confidence. And partly because of tax treatment: bonus shares aren't taxed as income when issued, unlike dividends which attract 10% withholding tax. Between 2000 and 2026, VCORE has recorded over 250 bonus share issues on the NGX.
Rights offerings are another common event. The company offers existing shareholders the right to buy new shares at a discount to the market price. If you don't participate, your ownership gets diluted. Stock splits (consolidations and subdivisions) happen less frequently but have the same mechanical effect as bonus issues on historical price adjustment.
Here's the problem most people don't think about. When Dangote Cement did a bonus issue, its share price dropped overnight by the bonus ratio. If you're looking at a raw price chart, it looks like the stock crashed. It didn't. The price was adjusted for the new shares. Same thing happens with stock splits and rights issues.
To build an accurate historical price series, every one of these events needs to be identified, dated correctly, and applied as an adjustment factor. Miss one bonus issue from 2008, and every return calculation before that date is wrong. Miss a 1-for-1 bonus (which doubles shares outstanding), and your historical prices are off by 100%.
This is where Nigeria's data infrastructure lets investors down. There's no single, reliable, machine-readable source of all historical corporate actions. Annual reports mention them. Broker circulars announce them. But assembling the complete history requires manual work across dozens of sources. VCORE's corporate actions database includes 307 split and bonus records validated against EODHD data, company filings, and NGX circulars.
VENOBLE INSIGHT
During VCORE's data validation, we found that EODHD (one of the major global data providers for African markets) had 11 artefact errors in their Nigerian dividend data, including a spurious Chemical and Allied Products record and an AXAMANSARD duplicate. We also identified a GSK N7.50 payment that needed reclassification from final dividend to special dividend. These aren't edge cases. When you're building indices from historical data, one misclassified corporate action can propagate errors across thousands of daily calculations.
Nigeria uses a distinctive convention for dividend and bonus timing. The qualification date (sometimes called the record date) is the date by which you must be a registered shareholder to receive the payment. The ex-date, when the stock starts trading without the dividend, falls one trading day after the qualification date.
This is the opposite of what happens in most developed markets, where the ex-date comes before the record date (typically T-1 under T+2 settlement). The Nigerian convention trips up foreign investors and data providers who assume the standard international approach. If you're writing code to process Nigerian dividends, getting this wrong means you attribute the price adjustment to the wrong day.
Other corporate actions have their own calendars. Bonus issues have qualification dates and crediting dates (when new shares appear in your CSCS account). Rights issues have provisional allotment dates, payment deadlines, and listing dates for the new shares. Each of these dates matters for different calculations.
A bonus issue (also called a scrip issue) is when a company gives existing shareholders additional shares for free, proportional to their current holding. A 1-for-3 bonus means you receive one new share for every three you already own. The share price adjusts downward by the same ratio, so the total value of your holding doesn't change on the day of the issue. Nigerian companies issue bonuses more frequently than most markets. NGX Group itself declared a 1-for-3 bonus for FY 2025. Bonus shares aren't taxed on receipt, unlike cash dividends which attract 10% withholding tax, which partly explains their popularity.
On the ex-date, the share price adjusts to reflect the corporate action. For a cash dividend of N5 per share, the price drops by approximately N5. For a 1-for-2 bonus issue, the price drops by about one-third (since you now have 50% more shares). The adjustment happens automatically at market open. The key point is that these price drops are mechanical, not declines in value. Your total position value remains the same; it's just split differently between price and shares (or price and cash, for dividends). Problems arise when raw price data doesn't reflect these adjustments, making the stock look like it crashed when it merely paid out.
The qualification date (or record date) is the cutoff: you must be a registered shareholder by this date to receive the dividend or bonus. The ex-date is when the stock starts trading without entitlement to the payment. In Nigeria, the ex-date falls one trading day after the qualification date. This is the reverse of the international convention used in the US and UK, where the ex-date typically precedes the record date. If you buy shares on the qualification date in Nigeria, you're still entitled to the dividend. If you buy on the ex-date, you're not.
Every untracked corporate action corrupts your return calculations. If a stock did a 1-for-1 bonus in 2015 and you don't adjust historical prices, every return figure before 2015 is overstated by 100%. Miss a N10 special dividend, and the stock's price chart shows a phantom crash on the ex-date. Over decades, with hundreds of events across the market, these errors compound into wildly inaccurate performance histories. This is one of the biggest challenges in Nigerian capital markets data, and it's why reliable corporate actions databases are considered basic infrastructure in every developed market.