Had a Jane Street interview in 2013 that still bothers me.
It was my 6th round. Final interview. The guy walks in carrying no laptop, no notebook, just a cold brew and what I later realized was a single IKEA tea candle.
He writes on the whiteboard:
food: $200
rent: $800
utilities: $150
candles: $3,600
family: dying
Then he turns around and says, βOptimize.β
I laughed because I thought it was a culture-fit bit. He did not laugh.
So I said, βWell, obviously you spend less on candles.β
He says, βAssume candles are non-discretionary.β
Okay.
I start building a model. Basic constraint satisfaction. Family survival as a soft penalty. Candles as a state variable. Maybe thereβs an arbitrage where you buy wholesale paraffin and convert the $3,600 line item into inventory.
He stops me.
βYouβre thinking like a consultant.β
Thatβs when I knew I was in trouble.
He says, βGive me a bid-ask on family dying.β
I say, βWhat?β
He says, βYouβre long candles, short family. Where do you make markets?β
I try to recover. I say the real issue is liquidity: rent and utilities are fixed, food is elastic, candles are emotionally inelastic. Therefore the optimal strategy is to securitize future candle enjoyment and borrow against it.
He nods for the first time.
Then he asks, βWhat time do you sell the candles?β
I say, βWhenever the market is liquid?β
He says, βBe more specific.β
I say, βUhβ¦ 10 a.m. Eastern?β
For the first time, he smiles.
He goes, βEvery day?β
I say, βEvery day.β
He says, βIn size?β
I say, βIn size.β
He says, βAnd what do we call that?β
I say, βMarket manipulation?β
The room gets very quiet.
He looks disappointed and writes something down.
βNo. We call it providing liquidity to candle ETFs during the U.S. cash open.β
I try to save it. βRight. Of course. The family isnβt dying because we underfunded them. Theyβre just experiencing temporary price discovery.β
He nods again.
Then he points back at the board.
I had missed it. The utility bill was $150, but candles provide light. You can zero out utilities.
I update the budget:
food: $200
rent: $800
utilities: $0
candles: $3,750
family: still dying, but now in a more capital-efficient way
He says, βHow confident are you?β
I say, β0.95.β
He smiles and circles candles.
β0.95 huh?β
Then he asks me to estimate how many leveraged longs get liquidated if we dump $3,750 of candles at 10:00:01 every morning for 90 consecutive trading days.
Needless to say I did not get the offer.