What (if any) trading sites allow a trade trigger or conditional order that can be used to close a position at the close of the day regardless of any other stop-limit orders? I'm attempting to trade while at work, and I do not want to go over margin requirements by holding a position past 4pm EST. I understand I can program a macro that'll do it as long as the power doesn't go out while i'm at work but i'm looking for something more solid or perhaps an internet site/software that will do it for me.
At Interactive it is no big deal to go over margin. If you get over the nighttime limit, IB will close you out automatically before 4. You have a little bit of control, as you can specify "liquidate last" on holdings. Things may not happen the way you want and you are NOT guaranteed great executions, however. When the IB "Robo-clerk" is chopping positions, things happen fast... Setup portfolio margin (>$100K accounts) and you may never go over if you are careful. You could also use the API and program your own closeout routines, or there may be third-party frontends you could buy. Liquidation amount is that amount of Customer's position that the Interactive Brokers system, pursuant to a proprietary algorithm, will automatically liquidate at the point at which the equity in Customer's account falls below Interactive Brokers' minimum maintenance margin requirement. The Interactive Brokers system is designed to liquidate Customer's most recent transactions in 100 share and 1-option contract increments, or such amount of shares or option contracts held by customer that, following liquidation, will provide the account with equity in excess of Interactive Brokers' minimum maintenance margin requirement at the time of liquidation.
Market on close but that is pretty dangerous in my opinion, cause you never know what you are going to get. I think the best solution is try to close out like 20 minutes to the close that way you can have some flexibility and not get trapped by other market on close orders.
I think MOCs will generally do a good job of getting you out automatically at 4pm and at a good price, unless you're trading illiquid stocks, in which case you probably want to handle your exit manually anyway to try to obtain better pricing. If you don't like MOCs and want to automate your exit at a certain time, you can use IB's "conditional order", so you place a market order which "activates" only at, say, 3:55pm. The order waits until exactly 3:55pm and gets placed as a market order automatically.