A CS2 trade-up contract is an in-game tool that turns many skins into one. Steam Support's trade-up page says you trade 10 normal or StatTrak weapon skins of the same rarity for one skin of the next highest rarity from one of the collections used. The output is random, but it can only come from the collections your inputs belong to. Valve has not published how the odds are split between collections. A community trade-up and floats guide written after the October 2025 update reports that each input adds an equal share, split evenly among the next-rarity skins of its own collection.
The output's float value is also set by the inputs. Valve has not published the formula either. The same community guide reports that each input float is first placed inside its own skin's float range, the positions are averaged, and that average is mapped onto the output skin's range. This is why traders pick inputs carefully to land a Factory New result, and why float capping is a whole skill of its own.
What are the trade-up contract rules?
All ten inputs must share one rarity. Steam Support says normal skins cannot be used with StatTrak skins and vice versa, and a StatTrak contract returns a StatTrak item. Inputs can come from any mix of collections, but a skin that is already the rarest in its collection cannot be used, and knives and gloves are never inputs. Since the 22 May 2026 update, Souvenir skins can be selected alongside normal skins; Valve's note says all Souvenir attributes are removed and the result is a single normal item one rarity higher.
For years the chain stopped at Covert, since there is no grade above it in a normal collection. The 22 October 2025 update extended contracts: five regular Covert skins can be exchanged for one regular knife or one regular pair of gloves from a collection of one of the inputs, and five StatTrak Covert skins for one StatTrak knife. You cannot choose which knife or finish you get.
Can you make money with trade-up contracts?
Sometimes. The tool is a gamble with known odds, so its expected value can be calculated. A contract is profitable on average only if the weighted value of all possible outputs is higher than the cost of the ten inputs after selling fees. Profitable contracts need cheap inputs from a collection with an expensive output, and the trade-up EV guide walks through the sum.
Run the numbers before committing, check the current prices of every possible output, and remember the result is one random roll. A positive expected value does not mean you win this time.