TradeStation Help
You can use the Bid, Last, and Ask buttons to select the price for a trade.
The actions take place when pressing Bid, Last, or Ask based on the Order Type:
The buttons display the current Bid, Last, and Ask values for the symbol entered in the Symbol box. In addition, the Bid button displays the bid tick indicator. Buttons do not appear until you begin typing a valid symbol in the Symbol box.
For instructions on how to display the bid, last, and ask buttons, see Displaying or Hiding the Bid, Last, and Ask Buttons.