金融市场作为卖出凭证的单据voucher of sale

• 12月13日那天有大批大笔卖单涌出，造成当日股市大跌。

  On December 13th, there were a great number of share sales, causing the stock market to crash.

• 整个大盘都淹没在一片卖单中。

  The whole market is flooded with sales vouchers.

转卖自己持有的定单以获取更多的利益to sell an order for profit