NYC's new socialist mayor Mamdani plans to redistribute wealth from landlords to tenants and nonprofits, which is bad news for property owners and investors in the financial capital of the world.

• Mamdani is pushing policies that take from rich landlords and hand the benefits to tenants or nonprofit groups.
• Critics call it a Robin Hood approach that punishes success and scares off capital.
• The worry is that if this works in NYC, other big cities could copy the playbook.
• NYC is the top US city by economic output, so anti-business moves there carry national weight.

Outlook: Expect pushback from landlords and Wall Street, and watch whether wealthy residents and businesses start leaving the city.