Leaving Sierra? Plan your 90-day ISO window
Calculator · free · no signup · pre-IPOSierra is pre-IPO. Left with vested ISOs? Model the 90-day exercise-or-forfeit decision and its AMT cost at any valuation: current 409A or an expected exit price.
Beta · invite-only · AlphaLatitude Inc. · Free Tools
Your grant
Tax inputs
Grant timeline
Recommended exercise quantity
Exercise all 10,000
With 10%/yr expected growth over the 3-yr hold, every share's expected after-tax gain exceeds its marginal AMT cost. Net value: $171,946 at horizon.
Net after-tax value vs. shares exercised
Each point is the expected after-tax NPV at your hold horizon if you exercise that many shares now and let the rest expire.
Year-by-year tax breakdown
You pay the higher of Regular tax and Tentative AMT per jurisdiction, then subtract Credit recovered. The result is Net tax. Hover any number for the bracket-by-bracket breakdown.
| 1 | 10,000 | |||
| 2 | 0 | |||
| 3 | 0 |
Federal AMT credit
Earned
$134,654
Recovered
$29,764
Remaining
$104,890
The AMT credit only recovers in years where regular tax exceeds AMT — typically a year with no ISO exercise. It carries forward indefinitely (Form 8801) and applies in any future tax year where regular tax exceeds AMT.
Estimates only. Excludes disqualifying dispositions, NSOs, multi-state moves, and AMT preferences other than ISO bargain elements. Long-term capital gains tax assumes a qualifying disposition (ISO held ≥1 yr from exercise and ≥2 yr from grant); state LTCG follows ordinary brackets except where the state grants preferential treatment (HI, ND, SC, WI, AR, NM) or has a dedicated LTCG-only tax (WA). Assumes you are within the $100K ISO limit (any portion of an annual ISO grant whose FMV at grant exceeds $100K is treated as NSO from the start, §422(d)). State AMT figures are 2025 (next-year values published in late 2026). Not financial advice.
QSBS note. If your shares qualify (typically pre-IPO C-corp grants held 5+ years), a federal rule lets you exclude up to $10M of gain on a future sale from federal tax. That single rule shifts exercise-timing math more than AMT does. (This is §1202 “qualified small-business stock”.) Modeled in beta, not here.
You solved the exercise window. The beta plans what comes after it: the new shares, your remaining equity, hedges, and taxes in one multi-year plan.
Request beta access →About Sierra
Sierra is a privately held AI company, headquartered in San Francisco, CA.
CX agents; Bret Taylor.
Equity grants at Sierra typically include incentive stock options (ISOs) and non-qualified stock options (NSOs).
Bret Taylor, former Salesforce co-CEO and Twitter board chair, and Clay Bavor, who led Google Labs, founded Sierra in 2023. The company builds AI agents that handle customer conversations for enterprises, replacing traditional contact-center workflows with software that can reason, take actions, and escalate contextually. Sierra reached $100 million in annual recurring revenue before the end of 2025. It raised $175 million in October 2024 at a $4.5 billion valuation, $350 million in September 2025 at $10 billion, and $950 million in May 2026 at $15.8 billion.
Sources: techcrunch.com · cnbc.com
OptionsAhoy is an independent tool and is not affiliated with, endorsed by, or sponsored by Sierra.
If you are leaving Sierra with vested incentive stock options (ISOs), most stock plans give you 90 days from departure to exercise or forfeit them. The calculator works at any valuation: enter your strike and the current 409A fair market value (FMV) or an expected exit price. It computes your window deadline, the alternative minimum tax (AMT) cost of exercising in full, and the partial-exercise share count that maximizes expected after-tax value.
All Sierra tools → · Use the generic Post-Termination ISO Exercise Calculator for any company.
Sierra equity questions
- I left Sierra. How long do I have to exercise my ISOs?
- Most stock plans give you 90 days from your departure date to exercise vested incentive stock options (ISOs); unexercised options are forfeited when the window closes. Tax law is slightly wider: ISO treatment requires you to have been an employee within 3 months of exercise (Internal Revenue Code Section 422(a)(2)), so options exercised under an employer-extended window are taxed as non-qualified stock options (NSOs). Check your grant agreement for Sierra's exact terms. The calculator above computes your deadline from your departure date, the alternative minimum tax (AMT) cost of exercising, and the share count that maximizes after-tax value.
- Does Sierra grant ISOs, NSOs, or RSUs?
- Equity compensation at Sierra typically takes the form of incentive stock options (ISOs) and non-qualified stock options (NSOs). Incentive stock options can trigger the alternative minimum tax (AMT) when you exercise.
- Are Sierra shares eligible for QSBS?
- They might be. Qualified small business stock (QSBS) under Internal Revenue Code Section 1202 can exclude federal tax on much of the gain when shares were acquired at original issuance from a C-corporation while its gross assets were under $50 million, and held at least five years. Whether your Sierra shares qualify turns on when you acquired them and the company's asset size at that time.
One piece of the puzzle.
OptionsAhoy plans your Sierra equity alongside hedging, vesting, and de-concentration, across bullish, neutral, and bearish market scenarios. Free during beta.