Trade: Ethereum ETF Flows on May 18?
Resolution criteria on PolyGram: This market will resolve to "Positive" if total Ethereum ETF flows on Monday, May 18, 2026 are greater than 0, and to "Negative" if they are less than 0. If flows are exactly 0, the market will resolve to 50-50. The resolution source is Farside Investors, specifically the ETF Flow tab available at https://farside.co.uk/eth/ in the "Total" column for the date specified in the title. The total flows will be considered finalized for that day once flows for all ETF providers have been published. If data for any ETF provider remains unpublished by 12 PM ET, 2 days after the date specified in the title, the market will resolve based on all available data published up to that time.
PolyGram is an on-chain prediction market where you trade YES or NO outcome shares with real USDC on Polygon. For this market, buy YES if you believe the event will happen, or NO if you think it won't. Your maximum loss is your stake — winning shares pay $1.00 each at resolution. Unlike sportsbooks, there is no house edge: prices are set by supply and demand from other traders and reflect the crowd's real-time probability.
- Liquidity
- $18
- Total Volume
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- 24h Volume
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- Open Interest
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Market outcomes
| Ethereum ETF Flows on May 18? | 50% YES | 50% NO |
Market context
On Monday, 18 May 2026, Ethereum spot ETFs across all providers will record their daily net inflows or outflows. The market settles based on whether the aggregate figure exceeds zero, with resolution sourced from Farside Investors' published ETF flow data. A 50–50 split occurs if total flows equal exactly zero. The current order book on Polymarket reflects a 50% implied probability, suggesting traders perceive roughly equal likelihood of positive versus negative flows on that specific trading day.
Ethereum ETF flows have historically exhibited substantial day-to-day volatility since the products launched in 2024. Weekly and monthly trends often prove more predictive than individual daily figures, yet single days can swing sharply based on spot price movements, institutional rebalancing schedules, and broader cryptocurrency sentiment. May 2026 will mark nearly two years of operational history, providing a larger dataset of comparable trading days against which to assess typical flow patterns and seasonal dynamics.
Traders should monitor Ethereum's price action in the weeks preceding 18 May, as directional momentum typically correlates with inflow behaviour. Macroeconomic announcements affecting risk appetite—particularly Federal Reserve communications or inflation data releases—often drive flows across crypto products. Additionally, any significant protocol developments, regulatory announcements, or shifts in institutional positioning announced before that date could materially influence whether flows turn positive or negative. Settlement depends on Farside publishing complete data from all ETF providers by 12 PM ET on 20 May 2026.
Wikipedia Context
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EthereumEthereum is a decentralized blockchain with smart contract functionality. Ether is the native cryptocurrency of the platform. Among cryptocurrencies, ether is second only to bitcoin in market capitalization. It is open-source software.
Resolution source
This market settles from the official outcome published at https://farside.co.uk/eth/. 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 "Ethereum ETF Flows on May 18?" are the same as any other PolyGram crypto-price 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.
- Sign in on polygram.ink with your email — no full KYC under $1,500 lifetime trading volume.
- Deposit USDC on Polygon (lowest fees, ~$0.01 per transaction) or Ethereum. Funds credit after 12 confirmations.
- 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.
- Size your position. If you stake 100 USDC at 50% YES, you'll receive shares that pay $200 if YES resolves true — a 100% gross return. If NO resolves, your shares are worth $0.
- 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.
- 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?
$0 in lifetime turnover and $18 of resting liquidity puts this market in the below the median by volume for crypto contracts on PolyGram. Order-book depth is thin — large orders may need to be split across the book or executed as limit orders.
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.
Frequently asked questions
What is the current probability for "Ethereum ETF Flows on May 18?"?
As of today, traders on Polymarket price this outcome at 50%. The number updates continuously as the order book clears. PolyGram mirrors the same live odds with locale-aware formatting and USDC settlement.
How does this market resolve?
Resolution is sourced from https://farside.co.uk/eth/. Settlement is executed by the UMA optimistic oracle on Polygon, with a 2-hour dispute window before payouts clear.
When does this market close?
This prediction market is scheduled to close on 18 May 2026. After the resolving event occurs, settlement typically clears within 24 hours once the UMA optimistic oracle confirms the outcome. All payouts are in USDC on the Polygon network.
How can I trade on "Ethereum ETF Flows on May 18?"?
To trade on this prediction market, create a free PolyGram account at polygram.ink, deposit USDC via Polygon, and place a YES or NO order on the outcome you believe in. You can learn more on our how-it-works page. Your maximum loss is limited to your stake — there is no leverage or margin.
What happens when the market resolves?
When the outcome is determined, winning YES shares pay out $1.00 each in USDC, while losing shares pay $0. Settlement is handled by the UMA optimistic oracle on Polygon — a proposer submits the result, a two-hour dispute window opens, and if uncontested, payouts are distributed automatically. You can withdraw your winnings to any Polygon wallet.
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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