Some call them “truth machines(真相机器)”. Prediction markets, in which punters(投注者) can bet on anything from the outbreak of war to what celebrities will wear, reveal in their prices the closest thing to humanity’s best guesses about the future. Such markets can provide both entertainment and economic benefit. If people and firms can discern(识别，辨别) risks and opportunities from market prices, they will make better decisions. Some might even trade to hedge their exposure(对冲风险敞口) to events: one American bet big against the government forgiving his student debt, allowing him to pay some down whatever happened.
有人称它们为“真相机器”。预测市场允许投注者押注从战争爆发到名人着装等一切事物，其价格揭示了人类对未来最接近最佳猜测的东西。这类市场既能提供娱乐，也能带来经济效益。如果个人和企业能从市场价格中识别风险和机遇，他们就能做出更明智的决策。有些人甚至可能通过交易来对冲事件风险：一名美国人重注押注政府不会免除他的学生贷款，这样无论结果如何，他都能偿还一部分债务。
So it is good that these markets have been growing. Volumes on Kalshi, the biggest such financial exchange, climbed to $33bn in June, a 40-fold year-on-year(同比) increase. The firm is reportedly seeking to raise funds at a $40bn valuation; Polymarket, its main rival, at $15bn. Yet both markets face growing pains(成长的烦恼). Neither has devised(设计，想出) a reliable way to settle contracts.
因此，这些市场的增长是件好事。最大的此类金融交易所Kalshi的交易量在6月攀升至330亿美元，同比增长40倍。据报道，该公司正寻求以400亿美元的估值融资；其主要竞争对手Polymarket的估值为150亿美元。然而，这两个市场都面临成长的烦恼。两者都没有设计出可靠的合同结算方式。
Bookmakers have long faced such problems. They dealt with them by building up a body of rules and precedent(先例，判例). Prediction markets have no such infrastructure to call on. The process at Polymarket’s main exchange, which is crypto-based, verges on the absurd(近乎荒谬). Its contracts are loosely worded(措辞松散) and often rely on “a consensus of credible reporting” to resolve them, inviting disputes. When markets are contested, the exchange turns to holders of a little-known cryptocurrency, UMA, to vote on which way a bet should close. A democratic resolution mechanism may sound attractive, but the “oracle”, as it is known, is gameable(可被操纵的). An investigation by The Economist has revealed that a handful of wallets control a majority of the ballot and that big Polymarket traders routinely vote on how to define the outcome of their own bets.(《经济学人》的调查显示，少数钱包控制多数选票，大交易者经常对自己赌注的结果投票。)
博彩公司长期以来一直面临此类问题。它们通过建立一套规则和先例体系来应对。预测市场却没有这样的基础设施可以依赖。Polymarket主要交易所（基于加密货币）的流程近乎荒谬。其合同措辞松散，常常依赖“可信报道的共识”来解决争议，从而引发纠纷。当市场出现争议时，该交易所会转向一种鲜为人知的加密货币UMA的持有者，让他们投票决定赌注应如何结算。民主解决机制听起来可能很有吸引力，但这个所谓的“预言机”是可以被操纵的。《经济学人》的一项调查显示，少数钱包控制了大部分选票，而且Polymarket的大交易者经常投票决定如何定义自己赌注的结果。