Taiwan's mandatory short covering: the last buy-in date, explained
Last updated: 2026-08-19
A Taiwan margin short (融券) must be bought back by 6 business days before the stock's stop-transfer date — the deadline ahead of shareholders' meetings, ex-dividend/ex-rights record dates, and cash capital increases. Miss it and the broker or securities finance company force-buys at market price starting the next business day. Not investment advice.
The rule: 6 business days before stop-transfer
Under Taiwan's margin trading operating rules (證券商辦理有價證券買賣融資融券業務操作辦法 Art. 76), a stock is closed to new margin short sales for 4 business days starting 6 business days before the issuer's stop-transfer date (停止過戶日) — and any existing margin short position must be bought back and returned no later than that same 6th business day. This is what traders call the "last buy-in date" (最後回補日).
What triggers a stop-transfer date
Three recurring corporate events trigger this: shareholders' meetings (股東常會/臨時會— Company Act Art. 165 bars changing the shareholder register within 60 days before an annual meeting), ex-dividend/ex-rights record dates (see our ex-dividend/ex-rights reference-price guide), and cash capital increases. The purpose is to lock in an accurate shareholder register so the real owner of record — not a short seller — gets the vote or the dividend.
If you miss the deadline: forced buy-in
A margin short position not covered by the last buy-in date is force-closed: the securities firm or the securities finance company (證金公司) buys it back at market price starting the next business day, without the trader choosing the price or timing. This is also recorded as a credit-trading default, separate from the ordinary margin-call/forced-liquidation mechanism covered in our margin & short-selling guide.
Margin short (融券) vs. securities lending (借券): different recall rules
This fixed, corporate-event-driven deadline applies to margin short sales (融券) through a broker/securities finance company. Securities-lending short sales (借券賣出) work differently: the borrowed shares are only due back when the loan's own agreed term ends, or if the lender exercises an early-recall right — there is no single TWSE-wide fixed date tied to every stop-transfer event the way there is for 融券. Don't assume the two follow the same calendar.
Where to check the exact dates
The Taiwan Stock Exchange publishes a stop-transfer/stop-short-selling advance notice table (停資停券預告表), free, listing each upcoming stock's stop-transfer date and the corresponding last buy-in date. Check it before assuming a generic rule of thumb applies to a specific stock's event.
FAQ
What is mandatory short covering, in one sentence?
It's the requirement that a margin short (融券) position be bought back by 6 business days before the stock's stop-transfer date, so the shareholder register is accurate for the triggering corporate event.
What exactly is the last buy-in date?
The 6th business day before the stock's stop-transfer date (停止過戶日). New margin short sales are also barred for a 4-business-day window starting on that same day.
Does 借券賣出 (securities-lending short) need to be covered too?
Not on the same fixed schedule. 借券賣出 is only due back when the loan's own term ends or the lender recalls it early — there is no single TWSE-wide date tied to every stop-transfer event the way 融券 has.
What happens if I don't cover in time?
The securities firm or securities finance company force-buys the position at market price starting the next business day, without you choosing the price, and it is recorded as a credit-trading default.
Is this the same as a margin call / forced liquidation?
No — it's a separate mechanism. A margin call (see our margin & short-selling guide) is triggered when your collateral ratio falls below 130%; mandatory short covering is triggered by a fixed corporate-event date regardless of your collateral level.
Where can I check the exact date for a specific stock?
TWSE's stop-transfer/stop-short-selling advance notice table (停資停券預告表), free and updated per upcoming corporate event.
Not investment advice. This is a factual summary of TWSE's margin-short mandatory covering rule (證券商辦理有價證券買賣融資融券業務操作辦法 Art. 76), not a recommendation about when to short or cover. Source: Taiwan Stock Exchange.