the.com/crown jewels

The one asset you'd grab if the building were on fire — literal or anatomical.

means The most prized, carefully guarded possessions of a person, nation, or organization — the stuff you'd never let go of.

from Literally, the royal regalia — crowns, scepters, orbs — used in coronations and kept under heavy guard, most famously the UK's set in the Tower of London. The phrase jumped from palace vaults into everyday speech as a way to mark whatever's most valuable and protected, and picked up a cheeky slang life as a euphemism for male genitals, playing on 'treasure you guard closely.'

literal origin
British coronation regalia, worth billions, technically uninsurable
business slang
a company's most valuable, often most defended, division
euphemism duty
also moonlights as a polite term for testicles
takeover defense
selling them to repel hostile bidders is literally called that
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