A CS2 trade reversal is the recovery tool built into Valve's trade protection system. If you lose control of your account, or you get tricked into a bad trade, you can reverse it yourself from the Trade History page on Steam without opening a support ticket. Every item that left your account in a CS2 trade in the past 7 days comes back, and every item you received goes back to the person who sent it.
Reversal is all or nothing. You cannot pick one trade and leave the rest. Steam reverses every CS2 trade in the window, including fair trades you were happy with. Once you confirm, the account is blocked from trading and from using the Steam Community Market for 30 days.
How do I reverse a CS2 trade on Steam?
Open your Steam inventory, go to Trade Offers and then View Trade History. If any trade in the last 7 days is eligible, a banner appears with the option to restore your items. Confirm, and Steam moves the items back. If a received item was already passed to another account it still comes back, because Trade Protected items cannot leave the account that received them during the window.
If your account was hijacked, secure it first. Change your password, remove unknown devices, revoke any Steam Web API key and check that your Mobile Authenticator is still on your own phone. Then do the reversal. Otherwise the thief may simply trade the items out again.
What does a trade reversal mean for buyers?
If you receive an item in a direct trade and pay the seller outside Steam, the seller can reverse that trade for 7 days and keep your money. That is why trading real money for skins with a stranger is now riskier than it used to be. Marketplaces that run peer-to-peer trades usually hold the seller's payout until the window closes, so a reversal returns the buyer's money as well. The trade protection and reversals guide covers what to check before you pay anyone.