他们已经看到了他们的股票价值下跌了不少.用英语怎么说？

他们已经看到了他们的股票价值下跌了不少.

They had already seen the value of their stock erode considerably.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

already

adv. 早已，已经，先前；

例句
He has already voted by absentee ballot...
他已进行了缺席投票。

seen

v. 看见( see的过去分词 )，观看，领会，考虑；

例句
Holiday spots have seen a dramatic revival and tourist chiefs are competing for a slice of the action.
各个度假点重又呈现出一派兴旺景象，旅游业的龙头老大们都在争着分一杯羹。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

value

n. 价值，价格，意义，涵义，重要性，（邮票的）面

例句
Cheques can only be accepted up to the value guaranteed on the card...
支票的承兑金额不可高于卡上所担保的数额。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

stock

n. 股份，股票，库存，树干，家畜；adj. 常备的，存货的，陈旧的；vt. 提供货物，备有；vi. 出新芽，囤积；

例句
...a disastrous rise in interest rates allied with a stock market slump.
股市下跌的同时，利率却在灾难性地上涨

erode

vt.& vi. 侵蚀，腐蚀；vi. 逐渐毁坏，削弱，损害；

例句
The value of the dollar began to erode rapidly just around this time.
刚好在这个时候，美元开始迅速贬值。

considerably

adv. 相当，非常，颇；

例句
We have a buoyant economy and unemployment is considerably lower than the regional average...
我们经济繁荣，失业率远低于地区平均水平。