AppliedNumeric answer

Your passive fills capture a half-spread of $2$ cents a share and earn a rebate of $0.2$ cents. On average the mid moves $3$ cents against you within a second of each fill. What is your net expected profit per share, in cents? (Give a signed number.)

Answer with a number. Fractions, powers and expressions like 23/6 or C(52,5) are read correctly in practice.

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Reading the fill: adverse selection

Reported in interviews at

Citadel Securities, Hudson River Trading

Your passive fills capture a half-spread of 222 cents a share and earn a rebate of 0.20.20.2 cents. On average the mid moves 333 cents against you within a second of each fill. What is your net expected profit per share, in cents? (Give a signed number.)

More market making questions

Your passive fills capture a half-spread of $2$ cents a share and earn a rebate of $0.2$ cents. On average the mid moves $3$ cents against you within a second of each fill. What is your net expected profit per share, in cents? (Give a signed number.)