The two broad markets did not move together
Washington, DC had a higher median sold price but longer average marketing time and a lower average sold-to-original-list ratio. Montgomery County had lower average days on market and a higher ratio, while its active-listing count rose year over year and DC's fell.
Why the comparison cannot rank the markets
The jurisdictions have different property mixes, condominium shares, neighborhood structures, price bands, and transaction composition. The $41,960 median gap does not value equivalent homes. The 23-day marketing-time gap does not predict how a specific Bethesda house compares with a Georgetown rowhouse or DC condominium.
Useful decision boundary
Relocating buyers and cross-border sellers can use the divergence to identify which local evidence must be refreshed. The final comparison should match property form, price band, condition, location, and decision date.