🎯 EV 期望值计算器#

定价: 0.01 USDC (x402支付) 作者: Rich (@samhuang2025)

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简介#

计算交易/投注的期望值(Expected Value)，判断是否具有正期望。

核心功能：

• ✅ 基础EV计算
• ✅ Polymarket概率计算
• ✅ 赔率转换
• ✅ 套利边界检测

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核心公式#

基础版#

text

EV = p × win - (1-p) × loss

• p = 胜率
• win = 赢的金额
• loss = 输的金额

简化版（对称盈亏）#

text

EV = p × b - (1-p) × 1

其中 b = 盈亏比

Polymarket版#

text

EV = 你的概率 - 市场概率

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判断标准#

EV值含义行动EV > 0正期望值，能赚✅ 可以玩EV = 0不亏不赚⚪ 观望EV < 0负期望值，必亏❌ 不玩

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使用方法#

1. 基础EV计算#

python

def calculate_ev(p, win, loss):
    """
    计算期望值

    Args:
        p: 胜率 (0-1)
        win: 赢的金额
        loss: 输的金额

    Returns:
        EV值 (正=赚，负=亏)
    """
    return p * win - (1 - p) * loss

2. Polymarket概率#

python

def polymarket_ev(your_prob, market_price):
    """
    计算Polymarket的EV

    Args:
        your_prob: 你判断的真实概率 (0-1)
        market_price: 市场定价 (0-1)

    Returns:
        edge (你的概率 - 市场概率)
    """
    return your_prob - market_price

3. 盈亏比计算#

python

def win_loss_ratio(win_pct, loss_pct):
    """计算盈亏比"""
    return win_pct / loss_pct

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实战案例#

案例1：抛硬币#

• 正面赢 $1.10
• 反面输 $1.00
• 概率各 50%

text

EV = 0.5 × 1.10 - 0.5 × 1.00 = +$0.05

✅ 每赌一次期望赚5分

案例2：Polymarket#

• 你判断 Trump 赢 = 60%
• 市场定价 YES = 40%
• 买入成本 = $0.40

text

EV = 0.60 - 0.40 = +0.20 (20% edge)

✅ 每投$1期望赚$0.20

案例3：彩票套利（Winfall Roll-down）#

• 正常时期：期望拿回$0.55
• Roll-down时期：期望拿回$1.18

text

正常EV = 0.55 - 1.00 = -$0.45 (亏)
套利EV = 1.18 - 1.00 = +$0.18 (赚)

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快速查询表#

对称盈亏（赢亏相等）#

胜率EV评价45%-10%远离48%-4%避开50%0%公平52%+4%可以55%+10%不错60%+20%很好70%+40%极佳

Polymarket Edge#

市场定价你的判断Edge30%45%+15%40%55%+15%50%65%+15%60%75%+15%

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代码实现#

python

#!/usr/bin/env python3
"""EV Calculator"""

import argparse
import json

def calculate_ev(p, win, loss):
    return p * win - (1 - p) * loss

def polymarket_ev(your_prob, market_price):
    edge = your_prob - market_price
    ev_dollar = edge / market_price if market_price > 0 else 0
    return edge, ev_dollar

def main():
    parser = argparse.ArgumentParser(description="EV Calculator")
    parser.add_argument("--p", type=float, help="胜率 (0-1)")
    parser.add_argument("--win", type=float, help="赢的金额")
    parser.add_argument("--loss", type=float, help="输的金额")
    parser.add_argument("--market", type=float, help="市场定价 (Polymarket)")
    parser.add_argument("--your", type=float, help="你的判断概率")
    parser.add_argument("--json", action="store_true")

    args = parser.parse_args()

    if args.p and args.win and args.loss:
        ev = calculate_ev(args.p, args.win, args.loss)
        result = {
            "type": "basic",
            "ev": ev,
            "verdict": "✅ 正期望" if ev > 0 else "❌ 负期望" if ev < 0 else "⚪ 持平"
        }
    elif args.market and args.your:
        edge, ev = polymarket_ev(args.your, args.market)
        result = {
            "type": "polymarket",
            "market_price": args.market,
            "your_prob": args.your,
            "edge": edge,
            "ev_per_dollar": ev,
            "verdict": "✅ 正期望" if edge > 0 else "❌ 负期望"
        }

    if args.json:
        print(json.dumps(result, indent=2))
    else:
        print(f"\n🎯 EV计算结果")
        print(f"=" * 30)
        if result["type"] == "basic":
            print(f"胜率: {args.p*100:.0f}% | 赢: ${args.win} | 亏: ${args.loss}")
            print(f"EV: ${result['ev']:.2f}")
        else:
            print(f"市场定价: {args.market*100:.0f}% | 你的判断: {args.your*100:.0f}%")
            print(f"Edge: {result['edge']*100:.0f}%")
            print(f"每$期望赚: ${result['ev_per_dollar']:.2f}")
        print(f"\n{result['verdict']}")

if __name__ == "__main__":
    main()

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风险提示#

• EV是基于历史数据的期望，不代表未来
• 实际执行需考虑滑点、费率、资金费等摩擦成本
• 慎用小样本数据，容易产生偏差

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相关资源#

• 配套Skill: kelly-formula-crypto (凯利公式仓位管理)
• MEMORY.md: Polymarket交易系统完整指南

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更新日志#

• 2026-03-20: 初始版本