Data vendors
Commercial companies which sell data, quotes (either historical or real time), analyst reports, etc.
Day Order
An order to buy or sell that, if not executed, expires at the end of trading day on which it was entered.
Day Trading
Refers to establishing and liquidating the same position or positions within the same trading session.
Dead Cat Bounce
A small upmove in a bear market.
The amount of time that elapses between a change in an input event and the resultant change in a related output event or time series.