Trade-Up Contracts — The Honest Math (And When They Actually Work)

The trade-up contract is one of Counter-Strike's most misunderstood features. Most players try one, lose money, decide it's a scam, and never touch it again. They're not wrong — most trade-ups are bad. But a small, well-researched subset of trade-ups have positive expected value, and they've been the bedrock of a few collector careers.

How the math actually works

Put in ten skins of the same rarity, all from the same collection or a mix of collections. You get back one skin of the next rarity up, randomly chosen from the outcomes of those input collections, weighted by how many of each collection you put in.

Float on the output skin is calculated as the average of the input floats, scaled to the output skin's float range. Pure StatTrak inputs produce a StatTrak output. Mixing collections splits the outcome pool proportionally.

Why most trade-ups lose money

The casino takes its cut in two places:

1. The 15% Steam Market fee on every sale.
2. The average output is worth less than 10× the average input in most collections, because the rare outcomes don't make up for the common ones.

Pick a random Restricted skin from the Chroma 3 case, multiply by 10, and the math almost always says "no." That's not a bug — Valve tuned it that way.

When trade-ups actually work

A trade-up is +EV (positive expected value) only when the output collection has a lopsided outcome pool: one or two outputs worth significantly more than the others. The classic example is collections that include a Souvenir-only Covert from a popular map, where the Classified-to-Covert trade-up has only two outcomes and one of them is desirable.

The other working strategy is low-float pure-collection trade-ups: pay a small premium for sub-0.01 Mil-Spec inputs from a single collection, and the output lands in the bottom of the Restricted float range. The Factory New version carries a premium that often outpaces the input cost.

The rules of a good trade-up

1. One collection only. Splitting collections rarely improves expected value.
2. Low float in, low float out. Always.
3. Run the math first. Use a trade-up calculator. If the calculator says negative EV, don't do it because "you have a good feeling."
4. Volume matters. Doing one trade-up is gambling. Doing fifty +EV trade-ups is a job.
5. Account for the 15% fee. It eats more profit than you think.

Trade-ups vs. case opening

Trade-ups are almost always better than opening cases if your goal is to grow value. You're picking your input pool, you control float, and you can choose +EV setups. Opening cases is pure variance with no skill input. If you enjoy the dopamine of opening, that's fine — try our free case game instead and keep your real wallet closed.