About the USP-S | Serum
USP-S | Serum is a Classified skin that drops from one of the 42 CS2 weapon cases, the CS:GO Weapon Case 2.
Valve released the CS:GO Weapon Case 2 on 8 November 2013.
Each open has a 1.6000% chance (about 1 in 63) of pulling it, as one of 2 Classified finishes. One in ten of those drops is StatTrak.
It sits in tier 3 of 5 (Mil-Spec to Rare Special) and ranks #62 of 77 finishes in the CS:GO Weapon Case 2 by top-wear Steam price.
Its Steam price runs from $72.11 to $128.63 across wears, against $30.79 to open the CS:GO Weapon Case 2 (case plus $2.50 key), so every wear is worth more than one open.
Cases that drop the USP-S | Serum
Chance per open = Valve's Classified odds divided by the number of Classified finishes in that case. StatTrak versions drop 10% of the time. Open any of these free in the simulator: demo, nothing won. 18+.
| Case | Chance per open | About 1 in | StatTrak | Cost / open | Released |
|---|---|---|---|---|---|
| CS:GO Weapon Case 21 of 2 Classified | 1.6000% | 63 | 0.16000% | $30.79 | 8 November 2013 |
USP-S | Serum wears, float ranges and prices
Steam market 7-day average prices from 2026-10-03. Our item data has no per-skin float cap, so the standard 0.00 to 1.00 scale and the five wear bands are shown. A wear without a price had no recent sales or does not exist for this skin.
| Wear | Float range | Price | StatTrak |
|---|---|---|---|
| Factory New | 0.00 to 0.07 | $128.63 | $74.09 |
| Minimal Wear | 0.07 to 0.15 | $73.82 | $65.60 |
| Field-Tested | 0.15 to 0.38 | $72.11 | $68.32 |
| Well-Worn | 0.38 to 0.45 | No price | No price |
| Battle-Scarred | 0.45 to 1.00 | No price | No price |
USP-S | Serum FAQ
What are the odds of getting the USP-S | Serum?
1.6000% per CS:GO Weapon Case 2 open (1 in 63). That is Valve's 3.20% Classified chance split evenly across the finishes in that tier. A StatTrak copy is one tenth of that, 0.16000% at best.
Which CS2 cases drop the USP-S | Serum?
Only the CS:GO Weapon Case 2. The cheapest to open is the CS:GO Weapon Case 2 at $30.79 including the key.
How much is the USP-S | Serum worth?
Factory New $128.63, Minimal Wear $73.82, Field-Tested $72.11 on the Steam market (7-day average, 2026-10-03). StatTrak sells for $65.60 to $74.09. Wears without a price had no recent sales or do not exist for this skin.
Other Classified finishes in the CS:GO Weapon Case 2
All CS2 skins by rarity · Open the CS:GO Weapon Case 2 in the simulator (demo, nothing won, 18+) · How CS2 case odds work
This is a free simulator for entertainment: a demo, nothing is won and no money is used. Odds are Valve's published odds; wear and Doppler phase splits are estimated models, not Valve figures. Item values are indicative Steam market prices. Counter-Strike 2 and its item images are property of Valve Corporation. CaseBattles is not affiliated with or endorsed by Valve. 18+ only. Responsible gaming.