CS2 Trade-Up Contract Guide 2026: Best Combos for Profit

CS2 trade-up contracts are one of the most misunderstood mechanics in skin trading — and one of the most profitable when used correctly. Most players treat them as gambling. Experienced traders treat them as arbitrage. The difference? Understanding the math and knowing where to source skins at the right prices.

This guide covers everything: how trade-ups work, the probability math behind them, five profitable combos active in 2026, and how to use CSBoard's P2P exchange to find the exact skins you need without the 15% Steam tax cutting into your margins.

How CS2 Trade-Up Contracts Work

A trade-up contract lets you exchange 10 skins from the same collection tier for 1 skin from the tier above. The rules:

• 10 skins — all must be the same rarity tier (e.g., 10 Mil-Spec skins → 1 Restricted)
• Same collection is NOT required — you can mix collections as long as the rarity matches
• Float inheritance — the output skin's float is calculated as the average float of your 10 inputs
• StatTrak matters — 10 StatTrak inputs give a StatTrak output (at ~10% odds); non-StatTrak cannot produce StatTrak
• Probability — each possible output skin has equal weight based on how many skins of that rarity exist across your input collections

The key insight most traders miss: the output probability is collection-weighted, not random across all CS2 skins. By choosing your 10 input skins carefully, you can control which collections are eligible for the output — and maximize the chance of hitting the most valuable result.

The Math: Expected Value Calculations

Before running any trade-up, calculate the Expected Value (EV):

EV = Σ (probability of each outcome × market value of that outcome)

Example: You're trading up 10 Mil-Spec skins at $2 each ($20 total cost). The possible outputs are 4 Restricted skins worth $5, $8, $12, and $35. If each has 25% probability:

• EV = (0.25 × $5) + (0.25 × $8) + (0.25 × $12) + (0.25 × $35) = $15
• Cost = $20
• EV/Cost = 0.75 → This trade-up loses money on average. Skip it.

A profitable trade-up has EV/Cost > 1.0, ideally > 1.15 after accounting for Steam Market fees. When sourcing skins through csboard.trade's P2P marketplace, you avoid the 15% Steam fee on inputs, which dramatically improves your margins.

How Float Affects Your Output

Float averaging is the hidden edge in trade-up math. The formula:

Output float = average of all 10 input floats

This means:

• Want a Factory New output? Average input float must be below 0.07. Use only Factory New or low Minimal Wear inputs.
• Want Minimal Wear? Keep average between 0.07–0.15.
• Using high-float (battle-scarred) inputs is only smart if the output looks better beaten up, or if you're just farming for StatTrak outputs.

For high-value outputs, always target the lowest float your budget allows. Factory New versions of rare skins can be 3–5× more valuable than Field-Tested.

5 Profitable Trade-Up Combos in 2026

1. Cobblestone Collection (Mil-Spec → Restricted)

The M4A4 | Jungle Tiger and AK-47 | Safari Mesh skins remain cheap inputs ($1.50–$2.50 each), while the Restricted tier includes the M4A1-S | Blood Tiger ($12–$18 in FT) and AK-47 | Jungle Spray ($8–$14). With careful float management to hit Factory New, this combo achieves ~1.2× EV regularly. Find cheap inputs on csboard.trade without the Steam Market surcharge.

2. Vanguard Collection (Restricted → Classified)

The Vanguard collection has one of the best Restricted-to-Classified ratios. Inputs like the MP9 | Sandstorm ($3–$5 each) can produce the coveted M4A1-S | Cyrex ($45–$80 in Factory New). The math: 10 × $4 input = $40 cost, with ~1-in-6 chance at the Cyrex FN = EV ~$12 from Cyrex alone plus other outputs. Positive EV when inputs are sourced below market.

3. Phoenix Collection (Restricted → Classified, StatTrak)

Using 10 StatTrak Restricted skins from the Phoenix collection (MP9 | Hypnotic, MAC-10 | Neon Rider) at $6–$10 each gives a ~10% chance at a StatTrak Classified worth $80–$150. The average case still returns around $18–$22 from cheaper outputs, making this one of the few StatTrak trade-ups with positive EV.

4. Clutch Collection (Classified → Covert)

The Classified tier of the Clutch collection is consistently underpriced. The MP5-SD | Phosphor and AUG | Stymphalian float around $18–$25 each. The Covert outputs include the M4A1-S | Master Piece (FN: $100–$150) and AWP | Hyper Beast (FN: $80–$120). This is a high-risk, high-reward combo — only attempt if you can source inputs below $20 each through P2P.

5. Operation Hydra Collection (Consumer → Mil-Spec, High Volume)

For traders on a tight budget, Operation Hydra Consumer-grade skins sell for $0.10–$0.30 each on P2P markets. Upgrading to Mil-Spec takes 10 inputs for a chance at $2–$5 skins. The margins are thin, but the volume potential is enormous — run 20 trade-ups per day and even a 1.05× EV compounds meaningfully over time.

Where to Source Skins for Trade-Ups

The biggest margin killer in trade-up trading is paying Steam Market prices for your 10 inputs. Steam's 15% seller fee means every skin you buy is 15% overpriced versus its true P2P value.

The smarter approach: use csboard.trade's P2P exchange platform to find traders willing to exchange skins directly. When both parties trade skin-for-skin, nobody pays a platform percentage. For bulk trade-up inputs (10 identical commons), this can save $3–$5 per contract — which is often the difference between positive and negative EV.

Practical workflow:

1. Calculate your target trade-up using the EV formula above
2. Search for your 10 input skins on csboard.trade
3. Find traders with matching inventory — propose exchanges using your current skins as currency
4. Accumulate all 10 inputs, then run the contract on Steam

Common Trade-Up Mistakes to Avoid

• Ignoring float on inputs: Mixing a 0.01 FN with a 0.85 BS averages to ~0.43 Field-Tested — you just destroyed value. Plan your float targets before buying inputs.
• Not calculating EV first: Running trade-ups without math is gambling, not trading. Always know your expected return before committing 10 skins.
• Forgetting collection weighting: If your 10 inputs span 5 different collections, you're spreading probability thin. Use inputs from 2–3 collections max and bias toward the one with the highest-value target skin.
• Using liquid skins as inputs: Some skins trade faster than others. Using highly liquid skins as trade-up fodder means you're sacrificing easy trades for uncertain upgrade outcomes.
• Ignoring StatTrak multipliers: A StatTrak output is worth roughly 2–4× a non-StatTrak equivalent. If the math works with non-StatTrak, it almost certainly works better with StatTrak inputs.

Final Thoughts

CS2 trade-up contracts reward preparation. The players making consistent profits aren't luckier than average — they're running positive EV contracts sourced through efficient channels. Do the math, control your float inputs, and source skins through P2P to protect your margins.

Start with the Cobblestone or Vanguard combos listed above. They're accessible at any budget level and have proven track records of positive EV in the current market. As you get comfortable with the mechanics, move up to higher-value collections where the margins — and the stakes — increase proportionally.

Ready to find skins for your next trade-up? Browse trader inventories on csboard.trade — P2P exchanges with no platform fees, just direct skin-for-skin trades.