Sensei Harbor Corp. Files Amended S-1: RSU & Capital Gains Tax Exposure Calculator (Sep 17, 2026)

What Changed

Sensei Harbor Corp. filed an amended S-1 registration statement on September 17, 2026. This marks a positioning step toward a public offering, though no pricing or share count has been disclosed in this amendment. For high-net-worth individuals holding pre-IPO equity or considering allocation in the offering, the 180-day lockup and tax treatment of restricted stock units become the primary variables.

The Numbers That Matter

Metric	Pre-IPO Private Holder	IPO Allocation Buyer	Post-Lockup Secondary Seller
Tax treatment on sale	Long-term capital gains (20% federal)	Short-term if sold under 1 year (37% top rate)	Long-term if held over 1 year from vest (20%)
Lockup exposure	180 days standard (6 months)	None	None
Withholding at vest	0% (not applicable)	0% (not applicable)	22% to 37% on RSU value at vest
Net proceeds on $500K position	$400K (post-tax, long-term rate)	$315K (if sold under 1 year)	$400K (if held through long-term threshold)

What This Means for Your Portfolio

If you hold $1M in pre-IPO shares and the offering prices at your 409A valuation, a sale immediately after lockup expiration would net approximately $800K after federal long-term capital gains tax. Selling in the first 180 days is not an option unless you negotiate an early release, which typically requires board approval and is rare outside executive packages. If you receive $1M in RSUs as part of the IPO compensation structure, the entire vest amount is taxed as ordinary income at rates up to 37%, reducing net proceeds to approximately $630K before any additional state tax.

Scenario Analysis

Portfolio Position Size	Post-Lockup Sale (Long-Term Gains)	Immediate Sale Post-Vest (Ordinary Income)	Net Difference
$500K	$400K	$315K	$85K
$1M	$800K	$630K	$170K
$2M	$1.6M	$1.26M	$340K

The $340K difference on a $2M position reflects the 17-percentage-point spread between the top ordinary income rate and the long-term capital gains rate. This analysis assumes no state tax and no additional Medicare surtax. California residents face 13.3% state tax on the ordinary income scenario, which would widen the gap by an additional $266K on the $2M position. New York residents face 10.9%, widening by $218K. The lockup period forces a holding period that converts what would otherwise be short-term gains into long-term treatment, but only if you acquired the shares more than one year before the IPO date.

The Constraint You Have Not Modeled

Most pre-IPO holders assume their cost basis is the 409A strike price from their option exercise. If you exercised incentive stock options more than two years before the IPO and held the shares for more than one year post-exercise, you qualify for long-term capital gains treatment on the full spread. If you exercised non-qualified stock options, the spread at exercise was already taxed as ordinary income, and your cost basis resets to the fair market value at exercise. That means your taxable gain at sale is only the appreciation from exercise to sale, not from grant to sale. On a $1M position where you exercised NQSOs at a $200K valuation and the IPO prices at $1M, your taxable gain is $800K, not $1M. At the 20% long-term rate, that is $160K in tax, not $200K. The $40K difference comes from basis step-up at exercise, which most holders forget to track.

Scenario Considerations

If you hold pre-IPO equity and the lockup expires in Q1 2027, consider modeling your sale against the April 15 tax deadline. A sale in January provides 15 months to plan liquidity for the tax bill. A sale in March compresses that window to 13 months and may require an estimated payment in Q2 2027. If you are receiving RSUs as part of IPO compensation, your plan may offer net settlement, which covers withholding automatically. Most plans default to sell-to-cover, which triggers a same-day sale and eliminates any holding period benefit. On a $500K RSU grant, net settlement withholds shares equal to the estimated tax liability at vest, while sell-to-cover withholds only the statutory 22%, potentially leaving a shortfall at filing if your effective rate is 37%.

Frequently Asked Questions

Q: Does the 180-day lockup count toward my long-term holding period?
A: Yes, if you already owned the shares before the IPO, the lockup period adds to your total holding period for capital gains treatment.

Q: What is my cost basis if I exercised ISOs three years ago?
A: Your cost basis is the strike price you paid at exercise, and the full gain from strike to sale price is taxed at long-term capital gains rates.

Q: How much of my RSU vest is withheld for taxes?
A: Default withholding under most plans is 22% federal statutory withholding. Your actual liability at the top bracket is 37%, which may leave a 15-percentage-point gap you must cover at filing.

Q: Can I sell pre-IPO shares in a secondary transaction before the offering?
A: Only if the company permits secondary sales and you find a qualified buyer, which typically requires board approval and is rare within 12 months of an anticipated IPO.

Run the Numbers

Use CalcMoney's Calculate Your After-Tax RSU Proceeds to see your exact figures under the current tax threshold.

Disclaimer: This article is for informational purposes only and should not be construed as personalized financial advice. Tax treatment of equity compensation and IPO transactions varies based on individual circumstances, holding periods, and jurisdictional rules. Consult a tax professional or financial advisor before making decisions regarding pre-IPO equity, RSU settlement, or timing of sales.

Run the Numbers: Capital Gains Tax Terminal on CalcMoney — see your exact figures under current market conditions.

Data sourced from SEC EDGAR S-1 Filings (IPO). Rates and thresholds are for informational purposes only. Consult a licensed financial advisor before making mortgage, investment, or tax decisions.

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