BSX operates a continuous first-come, first-serve order book. Orders are executed in price-time priority as received by the matching engine.

Self-Trade Prevention

Self-trading is not allowed on BSX. Trades between the same address cancel the taker order instead of causing a fill.

Order states

Order state	Description
`pending`	order is received but not processed yet
`open`	order is live on the book
`done`	order is either filled or canceled
`accepted`	stop order is accepted and resting. Order wont be placed on the book until being triggered.

Here are the possible values for cancel_reason field on the Order object

Reason	Description
`stp`	Order was canceled due to self-trade prevention
`time in force FOK`	Order was canceled because it couldn't be filled immediately in its entirety (Fill-or-Kill)
`time in force IOC`	Order was canceled because it couldn't be filled immediately (Immediate-or-Cancel)
`time in force GTT`	Order was canceled because it expired (Good-Til-Time)
`user`	Order was canceled by the user
`admin`	Order was canceled by an administrator
`liquidation`	Order was canceled due to liquidation
`insufficient liquidity`	Order was canceled due to insufficient market liquidity
`insufficient margin`	Order was canceled due to insufficient margin
`post only`	Order was canceled because it would have executed immediately (Post-Only)
`reduce only: pos size %s, order side %s`	Order was canceled because it would have increased position size (Reduce-Only)
`reduce only: pos size %s, order size %s, order side %s`	Order was canceled because order size was invalid for reduce-only order
`TPSL order canceled due to position closed`	Take-Profit/Stop-Loss order was canceled because the position was closed
`tpsl order cannot be larger than position: pos size %s, order size %s`	Take-Profit/Stop-Loss order size was larger than position size