Startup equity vs FAANG cash-flow modulator
Compare two tech offers on expected value, monthly cash flow, and risk: an established big-tech package with high cash base and liquid quarterly RSUs versus an early-stage startup package with lower cash and illiquid stock options. Evaluate how the answer changes across different venture volatility curves.
How the model works
The engine models annual cash inflows and tax liabilities for both offers over a user-defined horizon (1 to 10 years). Every dollar of after-tax income is discounted to present value (PV) using the discount rate, accounting for the opportunity cost of deferred or illiquid capital.
Offer A: Big Tech Cash Flow & Liquid RSUs
Base salary grows by the annual merit raise rate. Initial RSU grants vest according to either equal annual tranches (25/25/25/25) or back-loaded schedules (5/15/40/40). Annual refreshers awarded starting in year 2 vest over subsequent 4-year periods. Stock prices evolve via Geometric Brownian Motion (GBM):
The drift term ln(1 + μ) − 0.5σ² makes the expected annual stock growth equal to μ.
RSUs are treated as ordinary earned wage compensation upon delivery, subject to federal brackets, FICA with 2026 caps, and state withholding.
Offer B: Startup Equity, Dilution & Overhang
Stock options follow a standard 4-year schedule (25% at 1-year cliff, monthly vesting thereafter). Future share count dilutes across financing rounds:
At the liquidity event, senior liquidation preferences must be cleared in full before common shares receive proceeds under participating preferred:
For non-participating preferred, investors convert to common whenever exit valuation times their fully diluted ownership percentage equals or exceeds their preference overhang (V · p ≥ O), receiving own · V; otherwise gross equity equals own / (1 − p) · max(0, V − O).
The model treats all preferred stock as a single class with one conversion threshold. Real cap tables often have several series that convert at different exit values, so results are a simplification.
Risk preferences: Constant Relative Risk Aversion (CRRA)
Simple arithmetic averages (expected values) fail to capture the severe downside of startup failure. The model applies power utility with risk-aversion coefficient γ:
The Certainty Equivalent (CE) inverts the expected utility across all simulation runs. If Offer A provides a higher CE than Offer B, a rational risk-averse tech worker prefers Offer A even when Offer B has a higher raw arithmetic expected value:
Assumptions and limits
Federal ordinary tax brackets reflect Rev. Proc. 2025-32 inflation indexing ($16,100 Single / $32,200 MFJ standard deduction). FICA models the $184,500 Social Security wage base at 6.2%, plus 1.45% Medicare and 0.9% Additional Medicare surcharges above $200k/$250k.
Washington has no tax on wages. It taxes long-term capital gains above an annual standard deduction (shown as $278,000, the 2025 amount) at 7%, with 9.9% on taxable gain above $1 million after that deduction, so the higher rate begins at about $1.278 million of total gains. A separate 9.9% tax on household income above $1 million is scheduled to begin January 1, 2028 and faces a legal challenge. The model does not include it.
Alternative Minimum Tax (AMT) on incentive stock option (ISO) exercise is excluded from the default cash flow models. In reality, exercising unvested or vested ISOs prior to an exit can trigger substantial AMT liability on the spread between the 409A valuation and strike price. Consult a licensed CPA.
The QSBS Section 1202 toggle applies to federal capital gains tax only. For stock issued on or before July 4, 2025, a full exclusion requires holding for more than five years. For stock issued after that date, the exclusion is 50% after three years, 75% after four and 100% after five, with a per-issuer cap of the greater of $15 million or 10 times basis ($10 million for earlier stock). The model measures the holding period from issuance to the exit year and does not verify that the company or stock qualifies. California and several other states do not conform, so state tax remains payable. Consult a licensed CPA.
Tax data last verified October 24, 2026: federal ordinary brackets and standard deductions, Social Security wage base, Medicare surcharge thresholds, California SDI rate, QSBS Section 1202 parameters, and Washington capital gains figures. Other figures, including state brackets and long-term capital gains thresholds, were last updated when the tool was built and are being reviewed.
- v1.1 (October 2026): Added tiered QSBS Section 1202 holding periods and the $15 million cap for stock issued after July 4, 2025. Added the non-participating preferred conversion rule. Corrected Washington capital gains wording. Moved tax constants into a single sourced data object.
- v1.0 (September 2026): Initial release.
Frequently asked questions
Are startup stock options worth taking over liquid big-tech RSUs?
Startup stock options represent asymmetric upside with high variance. Most early-stage startups return little or nothing to common shareholders, and outcomes vary widely. Big-tech RSUs deliver liquid, deterministic cash flow every quarter that can be immediately reinvested or spent. Under standard risk aversion (CRRA utility), the certainty equivalent of guaranteed liquid comp frequently exceeds the expected value of illiquid options unless the startup achieves an exceptional exit.
How are RSUs and options taxed differently?
RSUs are treated as earned wages at the time of each vest, subject to ordinary federal income tax, state income tax, and FICA payroll taxes. The company typically withholds a portion of the shares to satisfy statutory tax obligations. In contrast, stock options incur no tax at grant. Upon exercise or exit, the spread between the fair market value and strike price is taxed either as ordinary income (NSOs or disqualifying dispositions) or as long-term capital gains if shares were early exercised and held for over one year (and two years from grant for ISOs).
What is a 409A valuation, and how does strike price relate to it?
A 409A valuation is an independent appraisal of the fair market value of a private company common stock, performed in compliance with IRS Section 409A. By law, stock options must be granted with a strike price at or above the fair market value determined by the latest 409A valuation. Preferred stock sold to venture capitalists typically commands a higher price per share than common stock due to protective provisions, dividend rights, and liquidation preferences.
How does liquidation preference overhang affect common equity?
Liquidation preferences ensure that preferred investors recoup their invested capital (typically 1× non-participating or participating) before common shareholders receive a single dollar of exit proceeds. If a startup raises $40M across multiple rounds and later sells for $35M, the preferred investors claim the entire $35M, leaving $0 for common option holders even though a company sale occurred. Non-participating investors convert to common when that pays more, so the overhang matters mainly at low and mid exits.
Why does risk aversion (CRRA utility) favor Offer A even when Offer B has a higher expected value?
Constant Relative Risk Aversion (CRRA) models the diminishing marginal utility of wealth: the pain of receiving near-zero equity in an unsuccessful startup outweighs the speculative pleasure of a massive windfall. Unless an engineer already possesses substantial baseline wealth, a risk-averse individual requires a certainty equivalent discount on volatile assets. This explains why rational engineers often prefer liquid $350k comp packages over startup packages with higher raw arithmetic expectations.
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