In the high-volatility market of 2026, putting 20% down is no longer an act of safety—it is a massive opportunity cost.
The PMI Bogeyman: Auditing the Real Friction
> Home Price: $500,000
> **Scenario A (20% Down):** $100,000 Invested. Monthly P&I: $2,528. PMI: $0.
> **Scenario B (3.5% Down):** $17,500 Invested. Monthly P&I: $3,049. PMI: $185.
> **Remaining Liquidity in Scenario B:** $82,500.
If you take that $82,500 and place it in a standard S&P 500 index fund, that capital generates $550 - $680 per month. Your "Net Mathematical Friction" for owning the home five years earlier is less than $150 a month.