Two-Outcome Market Simulator

This app simulates a 2-outcome prediction market, similar to Polymarket or Kalshi style. There are only two possibilities: either A happens, or A does not happen (so B happens). People each have their own belief about probability, and based on that belief they place offers.

Simple example: if I think A has a 55% chance, I might place a bid at 0.54 to get better odds. If another person is willing to sell at 0.53, the market matches that trade. The exchange keeps the difference (0.01) as profit in this simulation.

Live order arrivals Real-time matching Midpoint implied probabilities Exchange spread profit tracking

Number of offers to simulate Probability that outcome A happens according to general population 0.55 How much people disagree in their prices; higher means more variation (bettor_std) 0.05 Speed (higher value = faster arrivals)

0.6s per order

Orders Arrived

Matches

Implied P(A)

Implied P(B)

Exchange Profit

$0.0000

Market Field

Single field. Movement zones are invisible and defined by outcome/side.

Outcome A: Left side Outcome B: Right side Red text = Ask Green text = Bid

Implied Probability Over Time

Live midpoint-based implied probabilities.

A B

Match Log

#	Outcome	Bid ID	Ask ID	Bid Px	Ask Px	Spread	Trade Px	Cumulative Profit