Cerebras Systems (CBRS) Post-Termination ISO Calculator
Calculator · free · no signup · CBRSLeft Cerebras Systems with vested ISOs? Most plans give you 90 days to exercise or forfeit. See your deadline, the AMT cost of exercising, and the share count that maximizes after-tax value.
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 Cerebras Systems
Cerebras Systems (CBRS) is a public Semiconductors company, incorporated in Delaware and headquartered in Sunnyvale, CA. IPO'd May 14, 2026.
Last close: $220 per share (as of 2026-07-24).
IPO May 2026; wafer-scale AI compute.
Equity grants at Cerebras Systems typically include incentive stock options (ISOs), non-qualified stock options (NSOs), and restricted stock units (RSUs).
Cerebras Systems Inc., headquartered in Sunnyvale, California, develops semiconductors, supercomputers, and related software to power artificial intelligence deep-learning applications such as inference engines. Products include its wafer scale engine (WSE)-3 semiconductors, its CS-3 supercomputers, and its "AI inference cloud" and "AI training cloud" APIs, which allow users to access the company's computing power without buying its hardware. The company also builds data centers using its processors and supercomputers to provide cloud computing services directly to clients.
Source: Wikipedia (CC BY-SA 4.0)
Cerebras Systems makes the Wafer Scale Engine (WSE), a processor fabricated from an entire 300mm silicon wafer rather than the small dies that conventional chips use. Founded in Sunnyvale in 2016 by Andrew Feldman and four co-founders who had previously sold SeaMicro to AMD for $334 million, the company shipped its first system in August 2019. In January 2026, Cerebras signed a multi-year agreement to supply 750 megawatts of AI compute to OpenAI, a deal valued at over $10 billion. The company reported $510 million in 2025 revenue and listed on Nasdaq under the ticker CBRS in May 2026.
Sources: en.wikipedia.org · cerebras.ai · finance.yahoo.com
Equity comp at Cerebras Systems
- Original S-1 filed September 2024 was paused due to CFIUS review of UAE-based G42's investment (G42 accounted for 83% of 2023 revenue and 97% of 2024 hardware sales). CFIUS clearance reportedly obtained in early 2025 but IPO remained on hold; company raised $1.1B at an $8.1B valuation. Refiled S-1 in April 2026 with G42 removed from the investor list, targeting a May 14, 2026 NASDAQ listing under ticker CBRS. Holders face a concentrated tax-withholding event at IPO (about $230M earmarked for RSU settlement obligations) after roughly 18 months of regulatory uncertainty.
- RSUs use double-trigger vesting. Two things must both happen before the shares are yours: (1) the normal time-based vesting completes, and (2) the company has a liquidity event (an IPO or an acquisition). Until both happen, you do not yet own the shares and you do not owe tax on them.
Sources: sec.gov · techstartups.com
Researched 2026-05-11.
OptionsAhoy is an independent tool and is not affiliated with, endorsed by, or sponsored by Cerebras Systems.
If you have left Cerebras Systems (CBRS) with vested incentive stock options (ISOs), most stock plans give you 90 days from your departure date to exercise or forfeit them. Exercising everything at once concentrates the AMT bargain element into a single tax year. This calculator computes your window deadline from your departure date, the alternative minimum tax (AMT) cost of a full exercise at the current trading price, and the partial-exercise share count that maximizes expected after-tax value.
Example: leaving Cerebras Systems (CBRS) with 5,000 vested ISOs at a $66 strike, with the last close at $220, exercising all of them inside the 90-day window puts a $770,000 bargain element into one tax year. Above the 2026 federal AMT exemption ($88,100 single, $137,000 married joint), the 28% AMT rate adds roughly $215,600 on top of regular tax before any state AMT (CA, CO, CT, MN). Exercising fewer shares lowers that bill at the cost of forfeiting the rest; the calculator above finds the count that maximizes expected after-tax value for your exact figures.
All Cerebras Systems tools → · Use the generic Post-Termination ISO Exercise Calculator for any company.
Cerebras Systems equity questions
- I left Cerebras Systems. 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 Cerebras Systems'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 Cerebras Systems grant ISOs, NSOs, or RSUs?
- Equity compensation at Cerebras Systems typically takes the form of incentive stock options (ISOs), non-qualified stock options (NSOs), and restricted stock units (RSUs). Incentive stock options can trigger the alternative minimum tax (AMT) when you exercise. Restricted stock units are taxed as ordinary income when they vest.
- When did the Cerebras Systems IPO lockup expire?
- Cerebras Systems (CBRS) went public on May 14, 2026. The standard post-IPO lockup runs 180 days, so employee and insider shares generally became sellable around November 10, 2026. Confirm against your own grant paperwork, since some lockups release early or in stages.
- Do Cerebras Systems RSUs use double-trigger vesting?
- Yes. Cerebras Systems restricted stock units (RSUs) vest only when two things both happen: the time-based schedule completes, and the company has a liquidity event such as an initial public offering (IPO) or an acquisition. Until both occur you do not own the shares and owe no tax on them.
One piece of the puzzle.
OptionsAhoy plans your Cerebras Systems equity alongside hedging, vesting, and de-concentration, across bullish, neutral, and bearish market scenarios. Free during beta.