Polymarket Market Making: Automated Liquidity for Passive Profits

What Is Market Making?

A market maker continuously posts both buy and sell orders around the current price of an asset. When both sides fill, the maker captures the difference — called the bid-ask spread. On Polymarket, that looks like this:

• Bid (buy): $0.58
• Ask (sell): $0.60
• Spread captured: $0.02 per round-trip

The goal is not to predict which way the market moves — it is to collect that $0.02 spread thousands of times while keeping net directional exposure close to zero. Market makers are the engine that keeps order books liquid and prices efficient.

How Polymarket's CLOB Makes This Possible

Polymarket runs a hybrid-decentralised Central Limit Order Book (CLOB). Orders are matched off-chain for speed but settle on-chain via Polygon smart contracts using USDC. This design is what makes high-frequency market making viable:

• Off-chain order matching: Negligible gas costs for placing and cancelling orders — you can update quotes thousands of times per day
• Full API access: REST APIs for order management, WebSocket feeds for real-time order book data, and SDKs in multiple languages
• Binary outcomes: Every market has YES and NO tokens that mirror each other — a buy YES at $0.60 implies NO at $0.40, always summing to $1.00
• On-chain settlement: All positions settle transparently on Polygon, ensuring no counterparty risk

Two Revenue Streams: Spread Capture and Rewards

Market making on Polymarket does not just earn from spreads. Polymarket actively rewards market makers with daily USDC distributions through its liquidity rewards program, creating two simultaneous income streams:

1. Spread Capture

The primary income source. On a market with $100K daily volume and a 2-cent spread, a market maker capturing just 10% of the flow earns approximately $200 per day per market. Scale that across 10-20 markets and the returns become compelling.

2. Polymarket Liquidity Rewards

Polymarket distributes daily USDC rewards based on a scoring system that heavily favours automated bots:

• Spread tightness matters exponentially: The reward function is quadratic — being 1 cent from midpoint earns massively more than 5 cents away
• Two-sided quoting required: You must post both bids and asks to qualify for any reward
• Larger orders earn higher scores: Bigger resting orders increase your reward multiplier
• More markets compound rewards: Participating across many markets stacks daily payouts

The quadratic spread function is the key insight. It means tight, always-on quotes from automated bots earn exponentially more than manual traders who check in occasionally. This strategy fundamentally requires automation to be competitive.

Why Polymarket Market Making Is Unique

Binary resolution adds a twist absent in traditional market making. Every Polymarket contract resolves to exactly $1.00 or $0.00. A market maker holding excess YES tokens on the wrong side of an outcome faces total loss on that inventory at resolution. This makes inventory management the most critical component of the strategy.

Polysized's approach handles this with sophisticated inventory controls:

• Inventory skew adjustment: When the bot accumulates excess tokens on one side, it automatically widens the spread on that side and tightens on the other, naturally rebalancing over time
• Hard position limits: Maximum exposure caps per market prevent runaway accumulation on a single outcome
• Time-to-resolution awareness: The bot reduces position sizes and widens spreads as events approach resolution, minimising binary outcome risk
• Cross-market exposure tracking: Correlated markets are monitored as a group — e.g., individual candidate markets within the same election

How Polysized's Market Making Service Works

Polysized provides Market Making as a Service (MMaaS)— a fully managed solution that lets you earn from Polymarket liquidity without any technical overhead.

No One Else Is Doing This

The firms currently making markets on Polymarket are professional trading operations — Wintermute, Jump Trading, and independent quant teams running custom infrastructure. There is no retail-friendly, managed market making service for Polymarket. None.

Polysized is filling that gap. If you want exposure to one of the most consistent profit strategies in prediction markets — without building the infrastructure yourself — this is how you get it.