Oct 08, 2026 by Offer

What is arbitrage (Explained): Interview Answer Guide 2027

Arbitrage is the simultaneous purchase and sale of the same or equivalent assets in different markets to lock in a risk-free profit from a price difference. A strong arbitrage interview question answer names the mechanism — buy low in one venue, sell high in another, at the same time — and explains why true arbitrage is rare: competition erases it fast.

What the Arbitrage Interview Question Tests

Whether you grasp the core idea: risk-free profit from price discrepancies, not just clever trading.
Whether you can name real forms: spatial arbitrage, triangular FX arbitrage, ADR vs. ordinary shares.
Whether you understand why it disappears — efficient markets and fast competition close the gap.

How to Answer the Arbitrage Interview Question

Break the concept into its three essential parts:

Same economic exposure. You are long and short assets that must converge in value — the same stock on two exchanges, or an ADR and its underlying shares.
Simultaneous execution. Both legs go on at once, so market movement cannot hurt you between them.
Locked-in difference. The price gap, minus all costs, is profit the moment both legs fill.

Then add the honest caveat: textbook arbitrage is risk-free, but real-world frictions — latency, fees, failed fills — mean practitioners say "risk-free in theory, low-risk in practice."

Sample answer: "Arbitrage is buying and selling equivalent assets simultaneously to capture a price difference with no market risk. A classic example is a stock trading cheaper on one exchange than another. The reason you rarely see these chances is that competition closes them almost instantly."

Common Mistakes With the Arbitrage Interview Question

Calling any profitable trade arbitrage. If there is market risk, holding time, or uncertainty, it is speculation or relative value — not arbitrage.
Forgetting transaction costs. A price gap smaller than fees, spreads, and slippage is not an opportunity.
Ignoring execution risk: prices can move between your two legs, turning a 'risk-free' trade into a loss.

Trading firms ask about arbitrage because it tests whether you think in terms of risk or just profit. Candidates who volunteer the caveats — costs, latency, execution risk — stand out immediately from those who recite a textbook definition.

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FAQ

What is a simple example of arbitrage?

The same stock trading at $100.00 on one exchange and $100.05 on another. Buy at $100.00, sell at $100.05 simultaneously, and pocket the difference minus costs.

What is triangular arbitrage?

A three-currency loop in FX: convert currency A to B to C and back to A. If the cross-rates are misaligned, you end with more A than you started with.

Is statistical arbitrage true arbitrage?

No. Statistical arbitrage bets that historical price relationships will revert, but it carries real risk if the relationship breaks. True arbitrage is risk-free by construction.

Why don't arbitrage opportunities last?

Because every trader with the same data pounces at once. High-frequency firms now close most gaps in milliseconds, which is why retail traders rarely see them.

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