Electronic Market-Making Firms
What electronic market-making firms actually do — continuously quoting two-sided prices and earning the spread while managing inventory risk — and how that shapes the kind of work and interview you should expect there.
An electronic market-making firm's core business is simple to state and hard to do well: continuously post a buy price and a sell price for an instrument, capture the small gap between them on the trades that come in, and manage the resulting inventory so it doesn't accumulate into a large directional bet. Firms like this typically trade options, ETFs, futures, or crypto across many exchanges simultaneously, and their edge comes from speed, pricing accuracy, and disciplined risk management rather than from big directional views on where a market is headed.
What the work looks like
Traders and researchers at market-making firms spend their time on questions like: how wide should this quote be given current volatility and how informed the counterparty flow looks (see Quote Width and Adverse Selection)? How fast can pricing update when the underlying moves? How should inventory across thousands of related instruments be hedged efficiently? The pace is fast and the feedback loop is short — a bad pricing model shows up in P&L within hours, not months, which is part of why these firms lean heavily on rigorous testing before anything goes live.
What this means for interviews
Because the business model is "quote accurately, manage inventory, repeat, at scale," interviews at these firms lean heavily on trading games that simulate exactly this — see Making a Market: The Core Interview Game — along with probability, mental math under time pressure, and questions that test whether you instinctively widen out under uncertainty rather than hold a stale price. Strong candidates for these roles tend to enjoy fast, repeated, well-defined problems more than open-ended research questions.
| Trait | Market-making firm |
|---|---|
| Typical holding period | Seconds to days |
| Core skill tested | Speed, quoting discipline, probability |
| Source of edge | Pricing accuracy, latency, risk control |
| Interview style | Trading games, mental math, live quoting |
Market-making firms earn a living from the bid-ask spread across huge trade volume, not from big directional calls, which means their interviews and their day-to-day work both emphasize fast, disciplined, well-calibrated pricing over long-horizon conviction.
Further reading
- Baldwin, How to Build a Career in Securities Trading