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SPY (SPY) Up or Down on May 21?

How the prediction-market book is pricing "SPY (SPY) Up or Down on May 21?" right now, with a side-by-side platform comparison and zero-fee CTAs.

100% YES 0% NO Volume: $182K Closes: 21 May 2026
Trade on PolyGram →

Platform comparison

PlatformYES oddsNO oddsFeeKYCSettlement
PolyGram Pick
polygram.ink
100% 0% 0% (USDC on-chain) No-KYC up to $1,500 USDC, auto via UMA oracle Open on PolyGram →
Polymarket
polymarket.com
100% 0% 0% Geo-blocked in US/UK/EU USDC, on-chain Open on PolyGram →
Kalshi
kalshi.com
Up to 7% per trade US-only, KYC required USD Open on PolyGram →
Betfair Exchange
betfair.com
2-5% commission Full KYC from first trade GBP / EUR Open on PolyGram →
Manifold Markets
manifold.markets
Play-money (mana) None — play-money Mana (no cash-out) Open on PolyGram →

Live odds for Polymarket-based markets come from the Polygon order book. Non-Polymarket venues show attributes only; clicking any row opens the market on PolyGram.

Market context

This market will resolve to "Up" if the Close price for S&P 500 (SPY) on May 21, 2026 is higher than the Close price for S&P 500 (SPY) on the most recent prior trading day. This market will resolve to "Down" if the Close price for S&P 500 (SPY) on May 21, 2026 is lower than the Close price for S&P 500 (SPY) on the most recent prior trading day. E.g., ordinarily, a market on Monday would refer to the previous Friday for its most recent closing price, unless that Friday were a market holiday, in

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

What's the difference between YES and NO shares?
A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.
What does it cost to trade on PolyGram?
Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.
How fast are USDC deposits?
Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.
Do I need to KYC for this market?
Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.
How reliable are the quoted odds?
The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.

Trade SPY (SPY) Up or Down on May 21? on PolyGram

Live order book, 0% fees, USDC settlement in seconds.

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