The down payment decision

Sell the RSUs, or Borrow More?

The question every equity-heavy buyer agonizes over: liquidate appreciated stock for the down payment (pay capital gains now, cap the upside) — or keep the shares and carry a bigger mortgage. We run 4,000 market paths on your assumptions and show the full distribution, not a hunch.

Vested stock in question

The shares you could sell for the down payment

Cost basis

Basis as % of today's value (RSUs: value at vest)

Expected annual return

Your assumption for the stock — argue with it

Annual volatility

Single tech stocks typically run 30–60%

Capital gains rate

Combined federal + CA on the gain

Mortgage rate

30-year fixed — the hurdle your stock must beat

Holding horizon

How long before you'd sell anyway

Keep the shares & borrow — vs selling today

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Odds holding wins

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Median advantage

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Bad case (p10)

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Good case (p90)

Each bar is a slice of 4,000 simulated paths for your stock. Gold bars: holding beat selling. Grey bars: you'd have been better off selling today and shrinking the loan.

Model: your stock follows geometric Brownian motion at the return and volatility you set; selling today pays capital gains immediately and the proceeds avoid mortgage debt compounding at your rate; holding defers the tax to the horizon and carries the extra loan. Ignores dividends, AMT, wash rules, PMI, tax deductibility of interest, and concentration limits lenders may impose. An educational model of one trade-off — not investment, tax or lending advice. Talk to your CPA and advisor; we'll bring the housing math.