掺水股票指的是内在价值低于票面价值(face value)或设定价值(stated value)的股票。一般来说，公司股票之所以成为掺水股票，其主要原因可能是因为公司在发行股票时高估发起人投入的实物资产或无形资产的价值，从而使得公司股票的实际价值低于其票面价值或设定价值；或者是因为公司大量地向其发起人免费赠送本公司股票，造成公司实际资本并未增加而公司股票数量大幅增加，从而使得公司股票的实际价值低于其票面价值或设定价值。现在，随着各国对公司发行股票的监管力度的加强，公司发行掺水股票的现象已经很少见。相应地，公司通过发行掺水股票所筹集到的资本即为掺水资本(watered capital)，公司发行掺水股票的行为即为资本掺水(capital watering)。

掺水股票对应的英文为watered stock。其英文释义如下：Watered stock referred to shares of a company that were issued at a much greater value than the value implied by a company's underlying assets, usually as part of a scheme to defraud investors. The last known case of watered stock issuance occurred decades ago, as stock issuance structure and regulations have evolved to put a stop to the practice.

发行掺水股主要有3种情况：

(1)在公司增加资本或合并时，由于夸大公司现有资本总额并按夸大的资本总额发行股票，就能把握超出现有资本总额的那部分股票，进而控制公司活动。

(2)向发起人或雇员赠予或优惠提供股票，而不要求其支付正常费用。

(3)对公司的商业信誉等无形资产发行股票。由于掺水股与公司现有资产总额不符，无法真实地反映公司资产状况，不正常地降低了每份股票的价值并减少其股利，各国证券交易法已陆续禁止发行掺水股。

据说掺水股这一术语源于早前的农场主在将牛拉到市场上卖之前让牛大量饮水从而增加牛的体重这一典故。This term is believed to have originated from ranchers who would make their cattle drink large amounts of water before taking them to market. The weight of the consumed water would make the cattle deceptively heavier, enabling the ranchers to fetch higher prices for them.

以下为相关双语示例，供参考：

为保障小投资者的利益，政府当局应以有效方法处理"掺水股"的问题。 

In order to protect small investors' interest, the Administration should deal with the problem of "watered stock" in an effective way.