What Does "Don't Know" Mean?

Don't Know (DK) is a slang expression for an out trade that is used when there is a discrepancy in the details of a trade.

Also known as a "DK'd trade."

Understanding the Terminology

A DK'd trade can result when one of the parties to a trade has a dispute or rejects a trade for any number of reasons. They may not have the trade in their records or there may be a discrepancy with the price, cusip or number of shares. Occasionally, a party may use this tactic to get out of a trade when the market moves against them.

Example of Don't Know

For example, firm XYZ buys 1,500 shares of ABC stock from firm X. When firm X delivers the stock to firm XYZ, firm XYZ might reject the trade (DK it) if the terms of the delivery (price, quantity or specific security) don't match their records, or if the trade is not on their records.