Ex-dividend / ex-rights reference price: how Taiwan calculates it
Last updated: 2026-08-19
On a Taiwan stock's ex-dividend/ex-rights date, the exchange mechanically subtracts the dividend from the previous close to set a new reference price — the value isn't lost, it has simply moved from the share price into the dividend you're entitled to. Not investment advice.
What "ex-rights" and "ex-dividend" mean
A company distributes its profit to shareholders two ways: cash (a cash dividend) or additional shares (a stock dividend). "Ex-dividend" (除息) refers to the cash-dividend adjustment; "ex-rights" (除權) refers to the stock-dividend adjustment. Many companies pay both at once, which is why Taiwanese investors commonly say "除權息" (ex-rights-and-dividend) as one combined term.
The reference-price formulas
The Taiwan Stock Exchange publishes three cases. Cash dividend only: reference price = prior-day closing price − cash dividend per share. Stock dividend only: reference price = prior-day closing price ÷ (1 + stock dividend rate), where the stock dividend rate = stock dividend per share ÷ NT$10 par value (all TWSE/TPEx-listed shares carry a NT$10 par value). Both at once: reference price = (prior-day closing price − cash dividend) ÷ (1 + stock dividend rate) — cash is subtracted first, then the stock-dividend dilution is applied.
Why the price drops on the ex-date — and why that isn't a loss
The stock's price and the dividend it's about to pay both come from the same underlying company value. On the ex-date, the exchange mechanically moves the dividend amount out of the price and into what you're entitled to receive as a shareholder of record — total value on paper is unchanged at the moment of the adjustment. What happens after that is a separate question: the market can push the price back up (or down) based on ordinary supply and demand, independent of the mechanical adjustment itself.
"Filling" the gap vs. not filling it
If the share price climbs back up to (or past) its pre-ex-date level within some period, traders call that "filling" the price gap (填權/填息 — filling the rights-gap or the dividend-gap). If it stays below that level instead, that's called "not filling" (貼權/貼息). Whether a stock fills the gap depends on ordinary market demand after the adjustment — it is not guaranteed, and a stock's past fill record for one year doesn't guarantee the next. Not investment advice.
Where to check ex-dividend/ex-rights dates
Both exchanges publish this for free: the Taiwan Stock Exchange (TWSE) for listed shares, and the Taipei Exchange (TPEx) for OTC shares. Each publishes an ex-right/ex-dividend forecast table (upcoming dates and amounts) and a results table (the actual reference price after each adjustment).
FAQ
What is ex-dividend/ex-rights, in one sentence?
It's the mechanical price adjustment the exchange makes on the day a company's cash and/or stock dividend takes effect — the dividend amount is subtracted out of the share price and moved into what shareholders of record are entitled to receive.
What is the reference-price formula?
Cash only: prior close − cash dividend. Stock only: prior close ÷ (1 + stock dividend rate). Both: (prior close − cash dividend) ÷ (1 + stock dividend rate). The stock dividend rate = stock dividend per share ÷ NT$10 par value.
Why does the price drop on the ex-date? Did I lose money?
No — the value moves, it doesn't disappear. The price and the dividend both come from the same company value; the exchange's formula shifts the dividend amount out of the quoted price and into what you're entitled to receive. Your total position value is unchanged at the moment of adjustment.
What do "filling" (填權息) and "not filling" (貼權息) mean?
If the price climbs back to or past its pre-adjustment level, that's "filling" the gap (填權/填息). If it stays below instead, that's "not filling" (貼權/貼息). It depends on ordinary market demand after the adjustment — not guaranteed either way. Not investment advice.
How are cash dividends and stock dividends calculated separately?
The cash dividend is subtracted first (a flat NT$ amount per share), then the stock dividend's dilution is applied by dividing by (1 + stock dividend rate) — the stock dividend rate is the stock dividend per share divided by the NT$10 par value all TWSE/TPEx shares share.
Where can I look up ex-dividend/ex-rights dates?
Free from the official exchanges: TWSE for listed shares, TPEx for OTC shares — each publishes both a forecast table and a results table.
Not investment advice. This is a factual summary of the Taiwan Stock Exchange's ex-dividend/ex-rights reference-price mechanism, not a recommendation to buy, sell or hold around any ex-date. Sources: Taiwan Stock Exchange, Taipei Exchange.