Double-Trigger Acceleration

A vesting provision that accelerates unvested equity only when two events both occur: a company acquisition or change of control AND the employee losing their job as a result.

Double-trigger acceleration is a contract provision governing what happens to unvested equity when a company is acquired. The 'double trigger' refers to two conditions that must both be satisfied before acceleration kicks in: the first trigger is a change of control event (an acquisition, merger, or asset sale), and the second trigger is an involuntary termination or constructive dismissal that occurs within a defined window — typically 12 to 24 months — following that change of control. Only when both triggers fire does the employee's unvested equity automatically vest. Double-trigger acceleration has become the dominant standard in the venture-backed startup ecosystem because it protects employees from losing unvested equity due to an acquisition while also maintaining employee retention incentives for the acquirer.

The rationale behind the double trigger is a balance between two competing interests. Employees want protection from the scenario where a company is acquired and the acquirer immediately terminates them, leaving them with nothing from their unvested grants. Acquirers want to retain key employees post-acquisition by keeping their unvested equity as a retention incentive — if all unvested equity accelerated immediately on acquisition (single trigger), there would be no equity-based reason for employees to stay. The double trigger satisfies both: employees keep their unvested equity exposure and protection against being cut loose, while the acquirer retains meaningful retention leverage as long as they keep the employee employed.

The termination event that constitutes the 'second trigger' is critically important and worth reading carefully in your grant documents. Most double-trigger provisions cover both involuntary termination without cause AND constructive dismissal — meaning if the acquirer significantly cuts your compensation, materially demotes you, requires you to relocate, or substantially changes your responsibilities, you can resign and trigger the provision as if you had been fired. What qualifies as constructive dismissal varies by agreement and jurisdiction. A well-drafted double-trigger clause will enumerate specific constructive dismissal triggers: a reduction in base salary exceeding a threshold (commonly 10-15%), a significant reduction in target bonus, a relocation to a facility more than a defined distance (often 35-50 miles) from your current work location, or a material reduction in role responsibilities.

Not all unvested equity accelerates equally under double-trigger provisions. Some agreements provide for 100% acceleration of all unvested equity on a double trigger. Others provide for partial acceleration — commonly 12 or 24 months of additional vesting on top of whatever has already vested at the time of the double trigger. The most favorable outcomes for employees are full acceleration provisions negotiated at the time of hire or at the time of a promotion equity refresh. For executives and senior ICs, full double-trigger acceleration on all unvested equity is a realistic negotiating target. For junior employees, double-trigger provisions may be standard but partial rather than full. Equity without any acceleration provision — where the unvested equity simply disappears or is assumed (converted into acquirer equity) without protection — is common for standard employee grants and is the baseline you're negotiating up from.

What Triggers the Second Trigger

  • Termination without cause: fired or laid off within the post-acquisition protection window (typically 12-24 months after close).
  • Constructive dismissal — compensation cut: base salary reduced by more than the threshold in your agreement (often 10-15%).
  • Constructive dismissal — role reduction: material reduction in title, responsibilities, or authority — most agreements require the reduction to be 'material' but this is subjective and sometimes disputed.
  • Constructive dismissal — relocation: being required to work from a location more than a specified distance (commonly 35-50 miles) from your current office.
  • Constructive dismissal — bonus or benefits reduction: material reduction in target bonus or benefits package.
  • Notice and cure: most agreements require you to give written notice of the constructive dismissal condition and allow the company a cure period (30-60 days) before the second trigger is considered fired.

Negotiating Your Double-Trigger Provision

  • Seek full acceleration, not partial: '100% of unvested equity accelerates on double trigger' is significantly better than '12 months of additional vesting.'
  • Define the protection window broadly: 24 months post-close is better than 12 months — acquirers often wait out a shorter window before making changes.
  • Enumerate constructive dismissal triggers explicitly: vague language ('material reduction in role') is harder to enforce than specific thresholds ('base salary reduced by more than 10%').
  • Cover all equity grants: make sure the provision covers existing grants AND future grants — some agreements only cover the equity issued at the time of hire.
  • Watch for 'assumption' vs. 'acceleration': if your grants are 'assumed' (converted to acquirer equity), double-trigger may still apply; if they are 'settled' or 'cancelled with replacement,' the mechanics change.
  • Get it in the offer letter or grant agreement: a double-trigger promise made verbally or in a side letter is harder to enforce than one in the formal grant agreement.

Double Trigger vs. Single Trigger vs. No Acceleration

  • No acceleration (baseline): on acquisition, unvested equity is either assumed (converts to acquirer equity on the original schedule) or cancelled. You retain unvested upside only if you stay employed on the original schedule.
  • Single-trigger acceleration: all or a portion of unvested equity accelerates immediately on change of control, regardless of what happens to your employment. Rare outside of C-suite.
  • Double-trigger acceleration: unvested equity accelerates only if the acquisition happens AND you lose your job (or suffer constructive dismissal) within the protection window. The market standard.
  • Partial double-trigger: a defined number of months (12, 24) of additional vesting accelerates on double trigger — not necessarily 100%. Common for senior ICs and directors; full acceleration more common for VP+ and executives.
  • For senior hires: full double-trigger acceleration is a negotiating point worth pushing on, particularly if the company has raised significant venture capital and an acquisition is a plausible near-term outcome.

Example

A VP of Engineering joins a Series C startup with 400,000 unvested RSUs vesting monthly over four years. Her offer letter includes a double-trigger provision: 100% of unvested RSUs accelerate if (1) the company is acquired and (2) within 18 months of close, she is terminated without cause or suffers constructive dismissal. Eighteen months after joining, the company is acquired. She has vested 150,000 RSUs; 250,000 remain unvested. The acquirer retains her. Twelve months post-acquisition, the acquirer reorganizes and significantly reduces her team, removing her title, cutting her bonus target by 40%, and reassigning her reports to another executive. She provides written notice of constructive dismissal. The acquirer doesn't cure within 30 days. The double trigger fires — her 250,000 unvested RSUs accelerate immediately, now denominated in acquirer shares. Had her offer letter not included a double-trigger provision, she would have lost the unvested equity entirely upon resignation.