Trade: FTSE 100 (UKX) Up or Down on May 11?

Market context

The FTSE 100 will close on Monday, 11 May 2026, and this market resolves based on whether that closing price exceeds the previous Friday's close. The 99% implied probability reflects the order book's current positioning on Polymarket, where traders have priced in a strong likelihood of an up day. Single-day directional bets on major indices typically show modest edge; historical data suggests roughly 51–52% of trading days close higher than their predecessor across developed markets, though this varies by regime and volatility environment.

The current probability significantly exceeds the long-run baseline, suggesting either that traders expect specific positive catalysts or that the order book has compressed around a consensus view. May 2026 falls outside the typical earnings season for FTSE constituents, though economic data releases—particularly UK inflation figures, employment reports, or Bank of England communications—could influence sentiment in the days leading to settlement. Broader factors include US equity momentum, gilt yields, and sterling strength, all of which drive FTSE positioning. The settlement window closes at 20:00 GMT on 11 May, allowing traders to react to the official closing price published by the London Stock Exchange.

Traders should note that single-day index movements are inherently noisy; the 99% probability implies minimal compensation for execution risk and the possibility of unexpected volatility or data surprises. The gap between this implied probability and historical baseline rates suggests the market is pricing in either specific bullish positioning or a structural shift in how traders are weighting near-term UK equity direction.

Resolution source

This market settles from the official outcome published at https://www.wsj.com/market-data/stocks/emea. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.

How to trade this market step by step

The mechanics for trading "FTSE 100 (UKX) Up or Down on May 11?" are the same as any other PolyGram event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.

1. Sign in on polygram.ink with your email — no full KYC under $1,500 lifetime trading volume.
2. Deposit USDC on Polygon (lowest fees, ~$0.01 per transaction) or Ethereum. Funds credit after 12 confirmations.
3. Pick a side. Buy YES if you believe the event will happen; buy NO if you think it won't. The current YES price reflects the market's collective probability.
4. Size your position. If you stake 100 USDC at 100% YES, you'll receive shares that pay $100 if YES resolves true — a 0% gross return. If NO resolves, your shares are worth $0.
5. Set risk controls (optional). Stop-loss, take-profit, and limit-order types all supported. Use the trade ticket's slippage box to cap your maximum entry price.
6. Wait for resolution. When the event resolves on-chain via the UMA optimistic oracle, the winning side settles to 100¢ automatically and USDC hits your balance within seconds. Withdrawable to any wallet you control.

How active is this market?

$369 in lifetime turnover and $62K of resting liquidity puts this market in the below the median by volume for ftse contracts on PolyGram. Order-book depth is exceptional — among the deepest order books in the category.

Last 24 hours alone saw $367 in turnover, well above the lifetime daily-average for this market — a clear sign of news catalysing trader activity right now.

The market has been open for under a month — fresh enough that information asymmetry remains a real factor.

Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.

Key terms

YES / NO share

A binary outcome token that pays $1.00 if the underlying claim resolves true (YES) or false (NO), and $0 otherwise. The market price between 0¢ and 100¢ is the implied probability.

CLOB

Central limit order book. The matching engine that pairs YES buyers with NO buyers (effectively the same trade). Polymarket's CLOB on Polygon executes trades on-chain via the conditional-tokens framework.

Liquidity

USDC capital sitting in resting limit orders inside the order book. Deeper liquidity means smaller slippage on large trades and a tighter bid-ask spread.

UMA optimistic oracle

The on-chain dispute system that settles each Polymarket market. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution.

Slippage

The difference between the displayed mid-price and your fill price. Affects market orders most; limit orders avoid slippage but may take time to fill.

Conditional token

ERC-1155 outcome share issued by Gnosis Conditional Tokens on Polygon. The token type that resolves to $1.00 or $0.00 at settlement.

See the full prediction-market glossary →

Frequently asked questions

Risk and regulatory note

Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose.

Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.

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