What Is Single Trigger/Double Trigger Acceleration?

Single trigger/double trigger acceleration meaning

The meaning of single-trigger and double-trigger acceleration centres on fairness, protection and alignment during major corporate events. They define when and how unvested equity becomes fully or partially vested.

To define these mechanisms in practical terms:

• Single-trigger acceleration: vesting accelerates upon one event, typically a company sale or change of control
• Immediate vesting effect: equity may fully or partially vest at the moment the trigger occurs
• Employee-favourable structure: provides certainty that individuals benefit from an exit regardless of employment outcome
• Double-trigger acceleration: requires two events to occur before vesting accelerates
• Common trigger combination: a company sale plus termination without cause or a material change in role
• Investor-aligned structure: ensures employees remain incentivised to stay through the transition

A clear single vs double trigger definition highlights the difference between automatic acceleration and conditional protection.

Why acceleration provisions matter in equity structures

Acceleration clauses play a critical role in aligning incentives during exit scenarios, where interests between founders, employees and investors may diverge.

Their importance includes:

• Protecting employees and founders: ensuring they benefit from value created even if circumstances change
• Maintaining retention incentives: double-trigger structures encourage team continuity through acquisitions
• Balancing stakeholder interests: aligning outcomes between investors and operational teams
• Reducing uncertainty at exit: providing clear rules for how equity is treated
• Supporting negotiation clarity: acceleration terms are often key points in investment and acquisition discussions

For founders, choosing between single and double trigger acceleration can significantly affect team motivation and deal dynamics.

How acceleration works in practice

In a typical exit scenario, acceleration provisions are activated based on predefined conditions in option agreements or shareholder documents.

With single-trigger acceleration, vesting accelerates immediately when the company is sold. For example, an employee with unvested options may see all remaining options vest at closing, allowing full participation in the exit proceeds.

With double-trigger acceleration, the process is more conditional. Vesting accelerates only if the company is sold and the individual is subsequently terminated without cause or experiences a qualifying change in role. If the employee continues in their role post-acquisition, their vesting schedule may continue as normal.

This distinction is critical. Single-trigger acceleration prioritises immediate reward, while double-trigger acceleration prioritises retention and continuity.

Where Undo Capital fits in structuring acceleration terms

For founders designing equity incentives, Undo Capital provides practical guidance on structuring acceleration provisions that balance fairness with investor expectations.

Rather than defaulting to one approach, Undo Capital helps assess the company’s stage, team structure and likely exit scenarios. This ensures that acceleration terms support both retention and reward without creating unintended consequences.

By aligning vesting structures with long-term strategy, founders can build stronger teams and navigate exit events with greater clarity and confidence.