The Cold Start Problem: Why New Polymarket Events Struggle to Bootstrap Liquidity

A new prediction market launches on Polymarket to forecast the outcome of a significant regulatory decision. The event is structurally sound: the settlement oracle is specified, the outcome categories are mutually exclusive, and the smart contract is audited. Yet hours after launch, the market shows a bid-ask spread so wide that any meaningful trade would suffer substantial slippage. Volume remains near zero. Informed traders, who could provide price discovery and validation, stay away because the cost of entry—the gap between buying and selling—exceeds what they can profitably arbitrage. This is the cold start problem: a circular dependency in which markets need participants to become attractive to participants.

The problem is not unique to blockchain-based markets, but it is acute in prediction markets specifically. Unlike asset exchanges, where a token’s utility generates some baseline demand regardless of liquidity, prediction markets derive value entirely from participation. An event with poor liquidity becomes unreliable as a price signal. Traders therefore avoid it, which perpetuates the illiquidity, which ensures the market remains a poor signal. Breaking this cycle requires deliberate intervention, and the success of that intervention depends on understanding why cold start occurs and what mechanism can disrupt it enough to attract the first cluster of serious participants.

The mechanics of the cold start trap

Polymarket uses Automated Market Makers (AMMs) instead of traditional order books. An AMM is a smart contract that holds liquidity pools for each outcome and automatically adjusts prices based on the ratio of assets in those pools. When the market launches with minimal liquidity, any modest trade triggers a sharp price movement. This is the slippage problem: a trader buying $5,000 worth of one outcome might pay an effective price 20% worse than the quoted midpoint, making the trade unprofitable relative to the true underlying probability.

The effect cascades. Informed traders—those with genuine edge or hedging needs—will not enter a market where they lose money to slippage before they even face uncertainty about the outcome. Retail participants might accept bad pricing temporarily out of novelty or FOMO, but they do not represent the market’s integrity. Without informed traders, prices become arbitrary. Worse, when an informed trader finally does enter, they face a market so mispriced and illiquid that their initial scalp or hedge is constrained by whether they can actually exit the position without moving the price another 10 or 20 percent against them.

The AMM design makes this dependency explicit. The pricing curve is a mathematical function of the pool balances. A market with $100 in liquidity for a binary outcome (Yes/No) that starts at 50-50 odds will see prices jump dramatically on even $500 trades. Contrast that to an established market with $500,000 in liquidity: the same $500 trade moves prices by a fraction of a percent. The protocol is working as designed—the cost of moving the market is proportional to available liquidity—but the design does not self-correct when liquidity is very low. The market does not attract capital to improve itself; instead, the poor conditions repel it.

This dynamic is especially damaging for information aggregation, which is the entire purpose of prediction markets. If participants cannot enter and exit at reasonable cost, they cannot position based on their beliefs. The market therefore cannot function as a mechanism for surfacing dispersed knowledge. A Polymarket with a 5 percent slippage cost becomes a market where only traders with convictions so strong that they overcome that overhead will participate. That selects for noise as much as signal.

Why informed traders prioritize liquid markets

An informed trader has usually spent effort forecasting an outcome. They may have conducted research, built a model, or maintained a position in a related market. This edge has real value, but only if it can be realized. Realization requires two conditions: the trader must be able to enter the position at a cost lower than the value of their edge, and they must be able to exit before the market moves against them or before the underlying outcome is resolved.

In a thin market, both conditions are violated. The entry slippage can represent 3 to 10 percent of the trade size. For a trader with even a 15 percent conviction that an outcome is mispriced, that slippage is a major leak. They are starting the trade already underwater. Moreover, if they try to exit before resolution—perhaps because new information arrives or they want to lock in partial gains—they face the same slippage burden again. A round trip in a thin market can cost 15 to 30 percent, which erodes almost any edge.

Liquidity begets attention from informed traders, and informed traders beget liquidity. This is why established predictions markets on Polymarket—high-profile political races, major economic data releases, significant geopolitical events—attract professional traders, market makers, and capital. The liquidity is visible, the spreads are tight, and the price is therefore reliable. New markets, even on important topics, start with none of that. The first trader to enter a cold market is not just taking uncertainty about the outcome; they are also taking the risk that the market remains illiquid and they cannot exit at a fair price.

Structural barriers and network effects

The cold start problem reflects a more general network effect in markets. A market’s value increases with participation, but early participants face friction that later ones do not. This is not irrational behavior by traders; it is a response to genuine economic conditions. Slippage is a real cost, paid immediately, regardless of whether the trader’s forecast is correct.

Polymarket’s decentralized infrastructure also creates structural barriers that differ from traditional exchanges. There is no central authority that can subsidize a new market, offer preferential order routing, or use internal flow to provide interim liquidity. There are no market makers who are compensated for standing orders. The liquidity that exists is only what users have voluntarily provided or what the AMM holds from a launch configuration.

The platform’s zero-fee model on Polygon removes one friction point—traders do not pay per-trade fees—but it does not solve cold start. If anything, the structure makes it worse by removing a revenue source that might have been reinvested in liquidity provision or market operation. Instead, liquidity provision is purely voluntary. A user must decide that the potential return from market movement justifies the risk of being the only provider. In a new market, that calculus rarely works.

This also means that small prediction markets—those with modest total volume potential—may never achieve sufficient liquidity to function well. Once a market has been cold long enough, it becomes a permanent illiquidity trap. Users learn to avoid it, and the market gradually disappears from active attention.

Seed liquidity and the bootstrap intervention

Several approaches attempt to break the cold start cycle. The most direct is seed liquidity: an initial capital injection that provides depth to the AMM pools from day one. A market creator or organizer might deposit $10,000 or $50,000 into the Yes and No pools in equal proportions. This immediately allows traders to execute modest-sized trades at reasonable prices. The seed liquidity provider accepts the risk that no one ever trades—their capital might remain idle—but in exchange, they make the market viable for others.

Seed liquidity works, and it is used frequently on Polymarket for significant events. A major prediction market on Polymarket prediction markets often launches with thousands of dollars in seed capital provided by the event creator, market maker, or community organizer. The effect is immediate: spreads compress, volume increases, and the market begins to function. The original seed provider may or may not profit, depending on how prices move and whether the market ultimately attracts additional liquidity providers.

The weakness of pure seed liquidity is that it concentrates risk and cost in one actor. A market creator spending $50,000 to bootstrap a prediction market is betting heavily that others will value the market enough to keep it alive. If they do not, that capital has been consumed with little benefit to the network.

Anchor bets and conviction signals

An alternative approach is the anchor bet: a large, highly visible trade by a credible participant that serves as a signal of genuine interest and conviction. When a well-known trader, economist, or forecaster places a substantial bet on an outcome, it draws attention. Other traders notice, prices stabilize around the signal, and secondary traders begin to participate.

The mechanism is partly about information—if a credible person is betting money on an outcome, their forecast is worth considering—but also about coordination. An anchor bet provides a focal point. It suggests that the market is being taken seriously by someone with reputation and resources at stake. This lowers the psychological friction for others to enter. The second trader faces a market that looks less dead because the first trader has already moved the price and demonstrated that exit is possible.

Anchor bets are most effective when they come from sources with genuine forecasting credibility or subject-matter expertise. A bet by a hedge fund trader with a public track record carries weight. So does a bet by an academic or policy expert known for accurate predictions in their field. The bet need not be enormous; it must be visible and credible.

Anchor bets also create a natural feedback loop. If the bet attracts secondary traders, volume increases and prices become more reliable. If the anchor bet was informed—i.e., if the trader’s forecast was actually correct—then the market price will move in that direction, and the trader profits. This profit visibility then attracts more participation. Conversely, if the anchor bet was wrong, the market price moves against it, and secondary traders learn that the market is functional even when initial large participants lose. This also builds confidence in the market’s integrity.

Promotional incentives and conditional rewards

Some markets use promotional incentives to overcome cold start: trading rebates, liquidity provider rewards, or bonus USDC offered for participation within a specified window. These can be effective, though with caveats. A rebate program that reduces the effective cost of entry and exit can overcome slippage barriers. A user willing to take $1,000 in profit might trade in a market with normal slippage, but not in one where they would lose $200 to slippage. A 10 percent rebate flips that calculation.

The risk is that incentivized participation can be low-quality participation: traders chasing rewards rather than trading on genuine forecasts. This can degrade price quality rather than improve it. A market where 80 percent of volume is reward-seeking noise is often less informative than a market with half the volume but all informed traders. The price may be active, but it is not necessarily accurate.

More sophisticated incentive structures condition rewards on market health metrics. For example, rewards might be higher for trades that close wide spreads or for liquidity provision that persists across multiple days. These designs attempt to encourage the behaviors that matter for cold start resolution—sustained participation and active two-sided trading—while discouraging one-off reward-chasing.

The role of market creators and community coordination

In practice, the most successful cold start interventions combine seed liquidity with anchor bets and come from market creators or communities with genuine skin in the game. When a Polymarket on a specific topic is created by a researcher, organization, or group with real interest in the outcome, they often provide the initial liquidity, make the first visible trade, and use their reputation to attract secondary participants.

This is especially true for markets on niche topics. A prediction market on a specific regulatory outcome, scientific result, or corporate event might attract only a few hundred dollars of external interest. But if created by a stakeholder—a regulatory analyst, researcher, or firm with business exposure to that outcome—the creator can bootstrap it with their own capital and trading activity. Other participants then join as the market becomes visible and functional.

Community-driven markets can also overcome cold start through coordination. A group of forecasters who trust each other and recognize a market’s value might collectively provide seed liquidity, place anchor bets, or invite specific informed traders to participate. This requires social infrastructure outside the market itself, but it can be remarkably effective. The market becomes not just a mechanism but a focal point for a community’s aggregate knowledge.

The long-term view: Which markets survive cold start?

Not all new markets on Polymarket overcome cold start, and this is actually a feature of market efficiency, not a bug. Markets on outcomes that few people care about should remain illiquid. They should not attract capital and attention. The cold start problem is acute precisely for markets that matter: important events on which many people have forecasts but for which no bootstrapping has occurred.

The markets that successfully emerge from cold start typically share characteristics: they concern outcomes with genuine uncertainty and broad interest, they have creator or community backing, they launch with adequate seed liquidity or promotional support, and they attract at least one visible informed participant early on. The combination of capital and credibility breaks the circularity.

Markets that remain permanently illiquid are not a failure of the platform; they reflect accurate pricing of market value. If an outcome attracts zero external trading interest after reasonable promotional efforts, it suggests that the market’s information value is low or that interested parties lack capital or capability to participate. This is information about the market, not a defect in the mechanism.

The strategic question for market creators and platforms is how much subsidy is appropriate for bootstrap efforts. Seed liquidity has real opportunity cost. Capital tied up in a new market cannot be deployed elsewhere. Promotional incentives consume platform resources. Over time, Polymarket and its participants learn which bootstrap strategies produce efficient outcomes—markets that reach self-sustaining liquidity and price discovery—versus which ones produce zombie markets that require perpetual subsidization. The cold start problem will remain, but the solutions will become more targeted and capital-efficient.