The standard Bogleheads advice is always pay 20%. Here's how my situation is different:

- Can pay up to 2M liquidating stocks and bonds with no cap gains consequences

- Net worth of ~6.3M across cash, bonds, stocks and retirement accounts. Enough cushion to make a bigger downpayment

- Current interest rates are quite high - 5.5%

**Other factors**

- Early 40s, single earner. Annual comp ~$1.5M

- We save ~450K per year

- One child in elementary school, with 200K in 529 accounts

- Marginal income tax rate of ~50% (37% Federal, 12.3% State)

- Marginal capital gains tax rate of ~37% (25% Federal, 12.3% State)

Here's my current thinking. Is this right?

I can invest cash in S&P500, or pay down my mortgage.

**Paying down mortgage**

- First 750K of mortgage is at effective rate of ~3.6% after mortgage tax deduction (after accounting for the standard deduction).

This is same as getting a risk-free before tax return of 5.7% on the money

- After that, mortgage is at 5.5%

This is same as getting a risk-free before tax return of 8.7% on the money

**Buying S&P500**

Say, expected before tax return of 8%

**Conclusion**

I would choose a risk-free return of 8.7% over S&P 500. So pay down till mortgage is 750K

Beyond that, not clear. Risk free return of 5.5%, or risky return of 8% - depends on risk aversion.

But paying down mortgage till 750K seems clear.

Is this right?