Double trigger acceleration

What it means

Acceleration is a clause that vests unvested equity earlier than the schedule would. Single trigger acceleration fires on one event, normally an acquisition. Double trigger fires only when two events occur together: the company is acquired, and the holder is terminated without cause, or resigns for good reason, within a defined window after the deal, commonly nine to twelve months. Acceleration can be full, vesting everything, or partial, vesting some months of the remaining schedule.

Why it matters

It decides what happens to the largest financial asset most employees and founders have at the exact moment they have least control over it. Without acceleration, an acquirer can retain someone until just before a cliff or a large tranche and then let them go. With double trigger, being let go after an acquisition converts unvested equity into real value. It is the difference between a change of control being an opportunity and being a risk, and it costs nothing at all if the acquisition never happens. It is also one of the few equity terms an employee can realistically negotiate at the point of hiring.

Worked example

You hold 48,000 options on a four year monthly schedule with a one year cliff, and you are twenty four months in, so 24,000 are vested and 24,000 are not. The company is acquired and the buyer makes your role redundant three months later. With no acceleration you leave with the 27,000 vested by then and lose 21,000. With full double trigger acceleration all 48,000 vest on termination. At an exit price of EUR 4.00 a share against a EUR 1.00 strike, that difference is 21,000 shares at a EUR 3.00 gain each, or EUR 63,000. Partial acceleration is the middle case and the one most often granted: twelve months of the remaining schedule vesting on termination would convert 12,000 of those 21,000 unvested options, worth EUR 36,000 on the same figures.

The common mistake

Assuming it is there. Acceleration is not standard in employee grants and is frequently absent from the plan documents entirely, even at companies where the founders have it in their own agreements. Employees rarely ask because the topic feels remote at the point of joining. The other mistake is reading a single trigger clause as better in all respects: it is better for the holder, but a buyer who finds the whole team fully vested on completion may reprice the deal, and that cost lands on everybody.

In practice

Founders normally negotiate double trigger acceleration into their own arrangements at the first priced round, and investors expect the request. Senior hires often negotiate it individually. For everyone else it lives in the plan rules rather than the individual grant letter, so the question to ask is what the plan says on a change of control, not what your offer letter says. Ask before accepting, since it is far easier to add at the point of hiring than later. Where a plan is silent, the default is no acceleration at all, and silence is common.

What to ask

Ask what the plan rules say happens to unvested equity on a change of control, and ask for the plan document rather than a summary, because acceleration lives there and not in the offer letter. If there is acceleration, ask whether it is single or double trigger, how long the post-acquisition window is, and whether it vests everything or only part of the remainder. Ask what happens if the acquirer does not assume the plan at all, which is a real outcome and often unaddressed. If you are being hired into a senior role, ask for double trigger acceleration explicitly as part of the offer: it costs the company nothing unless the company is sold, which makes it one of the cheapest things you can be given. Ask before you accept the offer rather than after you start, because equity terms are negotiable at hiring and almost never afterwards.

Related terms

• Dead zone The band of exit values across which the common shareholders receive nothing extra, however much the price rises.
• Fully diluted shares The share count that assumes every option and every convertible has already converted. The only number worth quoting.
• 1x non-participating preference The founder friendly liquidation preference: money back once, or the percentage, whichever is larger, never both.