Market Making Strategies
In any market, a market maker is a participant that quotes both sides of a trade. In prediction markets, that usually means posting bids and asks around a fair-value estimate.
The core idea is simple: quote a buy price and a sell price, try to capture spread, and manage inventory so you do not end up with uncontrolled exposure.
Why it Matters
Prediction markets can be thin, especially outside the most active categories. Market makers help improve execution quality by keeping orders on the book, but that does not mean they face easy or risk-free profits.
How Market Making Works
The core strategy revolves around continuous quoting and inventory management, executed exclusively by programmatic trading bots.
1. Quoting the Spread
Assume the true mathematical probability of an event is exactly 50%. A market maker will look at the order book and place a limit order to Buy (Bid) shares at 48 cents, and simultaneously place a limit order to Sell (Ask) shares at 52 cents. The 4 cent difference is the spread.
2. Capturing the Edge
If Retail Trader A comes in and market sells at 48 cents, and minutes later Retail Trader B comes in and market buys at 52 cents, the market maker has successfully bought lower and sold higher. In the best case, they capture the 4 cent spread while keeping directional exposure small. If the market moves against them before they rebalance, that spread can disappear quickly.
3. Dynamic Rebalancing
If a sudden wave of news causes everyone to buy shares at 52 cents, the market maker's inventory becomes heavily skewed. They are now holding too much risk that the event will happen. The algorithm may shift its quotes upward (for example, bidding at 60 cents and asking at 64 cents) to discourage more buying and encourage selling.
Practical example
A simple order-book market maker might:
- estimate fair value at 50 cents
- quote a bid at 48 and an ask at 52
- shrink or widen quotes based on volatility and liquidity
- stop quoting if inventory becomes too one-sided
That is the basic workflow. The hard part is surviving real information shocks.
Risks: Toxic Flow and Inventory Risk
One of the main dangers for a market maker is toxic flow (also known as adverse selection).
Toxic flow occurs when the trader taking the market maker's offer has much better information. If a politician secretly resigns and insiders rush to the market before the news is public, they may buy the market maker's "Yes" shares at stale prices. Once the news breaks, the market maker can be left badly exposed.
Additionally, inventory risk happens when a market slowly trends in one direction over time. The market maker keeps buying as price falls, hoping to capture spread, but can end up accumulating too much of a losing position by expiration.
FAQ
Do exchanges pay market makers?
Sometimes there are maker incentives or fee differences, but you should not assume an active rebate program without checking the current platform documentation.
Can retail traders be market makers?
Yes, but it is highly competitive. Even a basic two-sided quoting bot requires much more than posting two orders and hoping for spread capture.
How does volatility affect market making?
Volatility can increase opportunity, but it also increases risk. Fast one-way moves are especially dangerous because they create adverse selection and inventory stress.