Optiver Trader OA (Intern / NewGrad) is a "mental math + market-making sim + probability reasoning" trio — totally different from the SWE Order Book / Allocation track. Below: 2026 spring cycle's training methods, simulator tools, and a one-week sprint.
Optiver Trading OA Snapshot (2026)
| Dimension | Detail |
|---|---|
| Platform | Proprietary online test |
| Duration | 80 questions × 8 min (mental math) + 25 min (market making) + 20 min (probability) |
| Difficulty | High-speed mental math + market-making intuition + probability |
| Grading | ≥ 60 mental math correct / market-maker PnL top 50% / probability all-correct |
| Logic | Bucketed sum + cadence consistency |
Line 1: 80 Questions in 8 Minutes — Mental Math
Features
- +/-/×/÷ + decimals + percentages
- e.g.
3.4 × 2.5 = ?,(160 - 17) / 11 = ?,12% of 850 = ? - 8 min / 80 = avg 6 sec per question
Training Method
- Master mental-math templates: ×11 (head + tail), ×25 (÷4 ×100), squared difference, etc.
- Timed Optiver 80in8 simulators: tradermath.org-style sites
- Decimals / percentages drill: 50 questions/day, target ≥ 90% accuracy
1point3acres reports: 60+ correct passes; 65+ leads to ~70% onsite invites.
Line 2: Market-Making Simulator
Mechanics
A virtual instrument with fair = 50. Markets push bid/ask quotes per second. Quote both sides — your spread controls inventory risk. 8 rounds, 3 min each.
Strategy
- Estimate fair fast from recent fills
- Control inventory: inv > 0 → tighter ask (want to sell); inv < 0 → tighter bid
- Manage spread: wider spread when volatility rises
- Avoid adverse selection: don't hold against persistent one-sided flow
class SimpleMaker:
def __init__(self, base_spread=0.4):
self.base = base_spread
self.inv = 0
self.fair = 50.0
def quote(self, mid, vol_proxy):
spread = self.base + 0.05 * vol_proxy
skew = -0.02 * self.inv
return (mid + skew - spread / 2,
mid + skew + spread / 2)
def fill(self, side, qty):
if side == 'B':
self.inv -= qty
else:
self.inv += qty
Optiver scores PnL ranking + inventory control. PnL-only chasers without inventory discipline get force-closed in the last round + score penalties.
Line 3: Probability Reasoning
Types
- Poker / dice / urn problems
- Decision tree + expected value
- Bayesian conditional probability
Examples
"Fair die rolled 4 times — probability of at least one 6?"
1 - (5/6)^4 ≈ 0.518
"Urn 1: 5 black 5 white; Urn 2: 8 black 2 white. Pick urn at random, draw black ball — P(Urn 2 | black)?"
Bayes: 0.8/13 → 8/13
Training Method
- 50 classic brain teasers (first two chapters of Heard on the Street)
- ≤ 60 sec verbal solution per problem
- Lead with symmetry / conservation / complementary events, not formulas
5-Day Sprint
| Day | Task |
|---|---|
| D1 | 200 mental-math questions, target avg ≤ 6 sec |
| D2 | 4 market-making sim rounds, log PnL + inventory path |
| D3 | 25 probability brain teasers, ≤ 60 sec verbal each |
| D4 | Full OA mock (mental math + MM + probability) |
| D5 | Gap drills + mindset (cadence, never overinvest in any single question) |
Real-Question Signals
- Cadence > single accuracy: skip 5 rather than burn > 10 sec on one
- Inventory awareness: MM round grades balance under flux
- Verbal intuition: Bayesian answers without formulas — explain why
FAQ
Calculator allowed?
No. Mental-math round explicitly bans calculators; MM round allows pen + paper but no on-screen tools.
Pass score on mental math?
60+ passes; 65+ correlates with onsite invites.
Same bank as SWE OA?
Completely separate. Trading: mental math + MM + probability. SWE: Order Book + Allocation algos.
Min prep time?
Mental math needs 2 weeks of consistent training to land 60+. MM needs 1 week of simulator + 1 full mock.
Preparing Optiver Trading OA / VO?
We were glad to help this cohort pass the Optiver Trading OA. Many candidates told us mental math speed can be drilled in days, but MM-round inventory awareness + probability-round verbal intuition can never be self-grinded — you need a mentor to lock the cadence.
If you're prepping Optiver, IMC, Akuna, SIG, or Citadel Securities Trader OA / VO and feel directionless, contact oavoservice. We tailor OA assistance to your gaps and connect mental math + MM intuition + probability narration into one practice loop.
👉 Add WeChat: Coding0201 — grab the Optiver Trading prep pack.
Contact
Email: [email protected]
Telegram: @OAVOProxy