Trade: SeaHorses Mikawa vs. Koshigaya Alphas

Market context

The Japan B League will host a matchup between SeaHorses Mikawa and Koshigaya Alphas on 3 May at 2:05 AM ET. The current order book on Polymarket shows zero demand for YES positions, reflecting a 0% implied probability. This extreme pricing typically emerges when one side of a binary contract receives negligible trading interest, leaving the book heavily skewed towards NO. The settlement window extends to 10 May, allowing for potential postponements or scheduling adjustments common in professional basketball leagues.

Historical context suggests that 0% probabilities in sports markets often indicate either genuine consensus about an outcome or insufficient liquidity to establish meaningful price discovery. Koshigaya Alphas have established themselves as a stronger franchise in recent B League seasons, though Mikawa has shown competitive capability in specific matchups. The complete absence of YES bids suggests traders have either heavily favoured Koshigaya or simply not engaged with this particular fixture, leaving the market vulnerable to sharp repositioning if new information surfaces.

Traders should monitor team roster announcements, injury reports, and any schedule changes through the B League's official communications before the 3 May fixture. Recent B League seasons have seen occasional postponements due to player availability or logistical constraints. The overnight timing of the match in ET may also affect trading liquidity, as participation from Western markets typically remains limited for early-morning Asian basketball fixtures. Any material roster changes or venue confirmations could shift the current extreme pricing.

Resolution source

This market settles from the official outcome published at https://www.bleague.jp/en/. 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 "SeaHorses Mikawa vs. Koshigaya Alphas" are the same as any other PolyGram sporting 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 0% YES, you'll receive shares that pay $200 if YES resolves true — a 100% 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?

$878 in lifetime turnover and $0 of resting liquidity puts this market in the below the median by volume for sports 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.

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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