Overview
The "Make Me a Market!" game is the single most common exercise in a trading interview, and this simulator drills it across a library of over 550 facts and guesstimates, organised into topic categories so you can practise exactly what you want. Pick a scenario, such as the height of a landmark or the number of piano tuners in a city, and you are asked to quote a two-sided market: a bid you would buy at and an ask you would sell at, without ever knowing the exact answer. The counterparty then trades against your quote, you take on a position, and you manage it through follow-up rounds and technical questions about your break-even and profit and loss.
Example: quoting the interviewer
The game runs as a conversation, the way the question is actually asked in an interview. You get a scenario, you post a bid and an ask with the size you are willing to do, and the interviewer trades against whichever side suits them. Then the spread tightens and you quote again.
How many bikes are there in Amsterdam?
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Show Inputs
How many bikes are there in Amsterdam? Please make a confidence interval of 95%.
Bid (Lower bound)
400,000
Ask (Upper bound)
1,400,000
Good, you should never get in the position that someone trades on your 95% confidence interval, because this simply means that either your market was not wide enough, or you wrongly estimated the mid market by miles. You did well!
Now please make me a new market with a maximum spread of 20 percent.
Bid Volume
1
Bid Price
800,000
Ask Volume
1
Ask Price
960,000
Next
The first answer is a 95 percent interval; after that you quote real markets. Too wide and nobody trades, too narrow and you get picked off, and each round the maximum spread shrinks.
Game Phases
1
Pick a scenario
Choose a fact or a guesstimate from a category, and set your preferences: a predefined spread or a fixed 5, 10 or 20 percent, whether to use trader language, and which technical questions to face.
2
Quote your market
Give a two-sided market, a bid and an ask, around where you think the true value sits. You will not know the exact answer, so the width of your market is your protection against being wrong.
3
Trade and manage the position
The counterparty buys your ask or sells your bid, leaving you long or short. Read the information you are given, adjust across follow-up rounds and keep your risk under control.
4
Answer the technicals
Between trades the game tests the maths behind your position with break-even and profit and loss questions, exactly like an interviewer probing whether you understand your own trade.
Scoring
1000
Starting balance
Every game begins with a balance of 1000. Your final balance when the clock runs out is your score for that scenario.
+P&L
Profitable trades
When the true value settles in your favour, the profit on your position is added to your balance, so a well-priced market that gets filled at good levels pays off.
L
Losing trades
When the value moves against your position, the loss is subtracted from your balance, exactly as it would be on a real book.
Spread
Market width
A wider market is safer but leaves value on the table; a tight market is rewarded when you are right and punished when you are wrong. Choose a predefined spread or lock it to 5, 10 or 20 percent.
Q
Technical questions
Break-even and profit and loss questions check the maths behind your trade. Getting them right keeps you in control of a position you actually understand.
Your score is the balance you finish a scenario with, starting from 1000. Because the counterparty trades against your quote, a tight market wins more when you are right and loses more when you are wrong, so the skill is pricing a two-sided market you can defend. During an interview it matters far more how you structure your thinking and manage the position than whether your estimate is exactly correct.
More Practice