Double-Trigger Vesting: Why Some Equity Only Vests If You’re Let Go After an Acquisition
A protection built into many tech equity packages that ties accelerated vesting to two specific events, not one.
Double-trigger vesting is an equity compensation provision requiring two separate events, typically a change of control such as an acquisition and the employee’s subsequent involuntary termination or resignation for good reason, before unvested equity accelerates and becomes fully vested.
Not financial advice. All figures for educational reference only. Data as at September 2026.
Key Takeaways
- Double-trigger vesting requires both a company sale or acquisition and a qualifying job loss shortly after, unlike single-trigger vesting, which accelerates equity on the acquisition alone.
- It’s designed to retain employees through an acquisition — since equity only accelerates if you actually lose your job, employees have less incentive to leave immediately after a deal closes.
- Common in startup and tech equity packages in Singapore’s growing tech sector, double-trigger clauses are typically written into stock option plans or restricted stock unit (RSU) agreements at the time of grant.
- The “second trigger” is usually defined narrowly — involuntary termination without cause, or resignation for “good reason” such as a significant pay cut or relocation — within a defined window after the acquisition, often 12 months.
- In Singapore, any accelerated equity gain is generally treated as employment income for tax purposes by IRAS, regardless of whether vesting was triggered by a normal schedule or an acceleration clause.
What Is Double-Trigger Vesting?
Vesting is the process by which an employee earns the right to equity, whether stock options or restricted stock units (RSUs), over time, typically according to a schedule, often four years with a one-year cliff. Vesting schedules exist to retain employees: if you leave before your equity vests, you generally forfeit the unvested portion.
Acquisitions complicate this. When a company is bought, what happens to employees’ unvested equity? Two common approaches emerged, particularly out of practice that has since spread to tech hubs including Singapore. Single-trigger vesting accelerates all unvested equity immediately upon the acquisition closing — employees get their equity regardless of what happens to their job afterward. Double-trigger vesting is more conditional: unvested equity only accelerates if two things happen — the acquisition (trigger one) and the employee subsequently loses their job involuntarily, or resigns for a defined “good reason,” within a set window after the deal (trigger two).
Double-trigger structures became the dominant standard in venture-backed tech companies because they solve a real problem with single-trigger vesting: if all equity vests the moment a deal closes, key employees have little financial incentive to stay and help the acquiring company integrate the business, potentially undermining exactly what the acquirer paid for. For Singapore employees at tech and startup companies with equity compensation, understanding which structure applies to their grant matters significantly if their employer is ever acquired.
How Double-Trigger Vesting Works in Singapore
The mechanics of double-trigger vesting are set out in the equity plan document and individual grant agreements employees sign when they receive stock options or RSUs. Trigger one is almost always defined as a “change of control”, typically an acquisition, merger, or sale of substantially all the company’s assets, with specific legal thresholds, such as a majority ownership change, spelled out in the plan.
Trigger two is where the real negotiation and nuance lies. It’s typically defined as either “involuntary termination without cause”, meaning the employee is let go, made redundant, or the role is eliminated as part of post-acquisition restructuring, or “resignation for good reason”, which usually requires the acquirer to have materially changed the employee’s role, compensation, or work location in a way defined in the agreement, for example a pay cut beyond a specified threshold, or relocation beyond a specified distance. This second trigger typically must occur within a defined window after the acquisition, commonly 12 months, though this varies by company.
If both triggers occur within the window, remaining unvested equity accelerates immediately, and the employee doesn’t need to wait out the rest of the original vesting schedule. If the acquisition happens but the employee keeps their job, or leaves voluntarily without “good reason”, the equity simply continues vesting on its normal schedule under whatever terms the acquiring company assumes or replaces it with.
For Singapore-based employees, any gain from equity that vests, whether on the normal schedule or via acceleration, is generally taxed as employment income by IRAS at the point of vesting, based on the market value of the shares at that time.
Worked Example
A Singapore-based software engineer joins a startup and receives an RSU grant of 10,000 units on a standard four-year vesting schedule with double-trigger acceleration written into her offer letter. After two years, 5,000 units have vested normally and 5,000 remain unvested when the company is acquired by a larger technology firm (trigger one).
Six months after the acquisition, the acquiring company restructures the team and eliminates her role as part of integrating overlapping functions, an involuntary termination that falls within the plan’s 12-month window (trigger two). Because both triggers have now occurred, her remaining 5,000 unvested RSUs accelerate immediately and vest in full at termination, rather than being forfeited as they would be under a standard schedule if she simply left.
Based on the acquiring company’s share price at vesting, those 5,000 shares are valued at S$150,000. This amount is treated as employment income for Singapore tax purposes and is subject to income tax in the year of vesting, alongside any final salary and severance payments she receives.
Advantages of Double-Trigger Vesting
Protects employees from being pushed out empty-handed. Without acceleration, an employee let go shortly after an acquisition could forfeit years of unvested equity through no fault of their own.
Aligns incentives better than single-trigger vesting. Because acceleration only happens if the employee actually loses their job, double-trigger structures don’t create a mass exodus of key talent immediately after a deal closes.
Provides a defined safety net during acquisition uncertainty. Employees know in advance the specific conditions under which their equity would accelerate, reducing ambiguity during what is often an unsettling period.
Encourages acquirers to retain rather than restructure aggressively. Because triggering acceleration has a real cost to the acquirer, it can create a mild incentive to retain rather than immediately eliminate acquired talent.
Risks and Limitations
Narrow definitions of “good reason” can leave employees unprotected. If the plan’s definition of qualifying resignation is too restrictive, an employee who leaves due to a genuinely worse situation that doesn’t technically meet the definition gets no acceleration.
The time window can expire before a layoff happens. If restructuring occurs just after the defined window, commonly 12 months, closes, an otherwise qualifying termination may not trigger acceleration at all.
Employees who stay don’t benefit from acceleration. If you keep your job after an acquisition, your equity simply continues on its normal schedule — double-trigger vesting offers no benefit if you’re retained, only if you’re let go.
Tax timing can create a cash flow mismatch in Singapore. Accelerated vesting can concentrate a large taxable gain into a single year, which may push an employee into a higher marginal tax bracket without an equivalent cash windfall if shares aren’t immediately liquid.
Double-Trigger Vesting vs Single-Trigger Vesting
The two acceleration structures differ in exactly one crucial condition:
| Feature | Double-Trigger Vesting | Single-Trigger Vesting |
|---|---|---|
| Acceleration condition | Change of control AND involuntary termination | Change of control alone |
| Employee retained after deal | No acceleration — normal schedule continues | Equity vests regardless of job status |
| Employee let go after deal | Full acceleration of unvested equity | Already fully vested at deal close |
| Acquirer’s perspective | Preferred — retains talent incentive | Less common — can create retention risk |
| Prevalence in modern tech grants | Common, especially post-2010s venture-backed companies | Less common today, seen in older-style grants |
Source: General equity compensation plan structures common in venture-backed technology companies; exact trigger definitions vary by company and grant agreement — always refer to your specific plan documents.
The Bottom Line
Double-trigger vesting is a protective mechanism, not a guarantee of payout — it only helps if you’re actually let go within a defined window after an acquisition. For Singapore employees holding equity in a startup or tech company, knowing whether your grant has single-trigger, double-trigger, or no acceleration provisions at all is essential information to have well before any acquisition rumour becomes reality.
Frequently Asked Questions
What is the difference between single-trigger and double-trigger vesting?
Single-trigger vesting accelerates unvested equity as soon as an acquisition closes, regardless of what happens to the employee’s job afterward. Double-trigger vesting requires both the acquisition and a subsequent involuntary termination, or qualifying resignation, before acceleration occurs.
Does double-trigger vesting apply automatically to all startup equity grants?
No. Whether double-trigger acceleration applies depends entirely on the specific equity plan and grant agreement an employee signed — it’s a negotiated or company-standard provision, not a universal legal requirement.
What counts as “good reason” to resign under a double-trigger clause?
This is defined in the specific plan document, but commonly includes a significant pay cut, a materially different role or reduced responsibilities, or relocation beyond a specified distance, all typically within a defined post-acquisition window.
Is accelerated equity from double-trigger vesting taxed in Singapore?
Yes. Gains from equity that vests, including via acceleration, are generally treated as employment income by IRAS and taxed based on the market value of the shares at the point of vesting.
How long is the typical window for the second trigger to occur?
A common structure is 12 months after the acquisition closes, though this period is set by the specific equity plan and can vary between companies.