Expected Value (EV) in CS2 Trade-Ups Explained
Expected Value (EV) is the mathematical foundation of profitable CS2 trading. It tells you the average return you'd get from a trade-up contract if you could run it infinitely. Understanding EV separates gamblers from traders.
Calculate EV Automatically →What Is Expected Value?
Expected Value (EV) is the probability-weighted average of all possible outcomes. For a CS2 trade-up:
EV = Σ (probability_i × price_i)
Where each possible output skin contributes its probability times its price. After subtracting the 13% Steam fee:
Net EV = EV × 0.87
If Net EV > Total Input Cost, the trade-up is positive EV (profitable over time).
EV vs. Single-Trade Outcome
EV tells you the average. Individual results will vary — sometimes a lot:
- A contract with 150% EV might return 50% on one run and 300% on the next
- High-variance contracts (few expensive outputs) need many runs to realize EV
- Low-variance contracts (many similarly-priced outputs) give consistent results
Key insight: A contract with 200% EV but only a 5% chance of the valuable output needs 20+ runs to expect profit. One with 140% EV but consistent outputs might be better for small bankrolls.
How TradeUpX Calculates EV
The scanner evaluates EV by:
- Identifying all possible output skins for a given input combination
- Looking up current market prices for each output (per wear condition)
- Calculating the output float for each possible skin using the CS2 formula
- Determining the probability of each output based on collection distribution
- Computing weighted average: Σ(probability × price × 0.87)
- Comparing to total input cost to determine ROI
This happens for every possible contract across all collections — thousands of combinations evaluated in seconds.
Positive EV ≠ Guaranteed Profit
A positive-EV trade-up is expected to profit over many runs, but:
- Price changes: By the time you sell the output, the price may have dropped
- Liquidity risk: If nobody buys your output, EV doesn't matter
- Sample size: Running 3 positive-EV contracts doesn't guarantee profit. Running 50 comes much closer.
- Data accuracy: EV is only as good as the price data. Stale prices = wrong EV.
Treat EV as your compass, not a guarantee. Refresh prices before buying inputs, and prefer contracts with multiple valuable outputs.