Held until you confirm receipt.
Escrow holds your money between paying and receiving. Nexus runs standard 2 of 3 multisig.
You fund the order, the vendor ships, you confirm receipt, and the coin releases. If you never confirm, the order auto-finalises after a few days so a vendor is not left waiting on an absent buyer. Disputes route through moderators who read signed evidence from both sides.
Confirming receipt before the package arrives, finalising early, releases the coin to the vendor and removes the dispute path. New vendors are locked out of finalise-early until they have run clean orders, and the profile shows their standing. Never finalise early on an unproven vendor.