All you have to do is simply not place orders that exceed your balance. Orders are easy to see from the portfolio "my orders" tab or from separate security trade screens and unlike your debit card example there are no overdraft fees. Also when a trade executes and other trades need to be cancelled the system seems to cancel your lowest bids first, notifies you on screen instantly, and issues an email. This isn't credit and there are no margin calls. It's merely a system that increases liquidity and allows investors to maximize the effect of available capital.
Like I said... without the ability to disable that feature for myself, I won't be very likely to trade there...I don't expect you to make it optional, just to get me to trade there... just offering my reason for my choice.
If it doesn't prevent my placing an order, due to insufficient funds, then it isn't acceptable.
From what I've heard, one of the strengths of your system(s) is the amount of features that you have been making available that sites like GLBSE lacked, for the users' benefit. Giving us the flexibility to tailor our experience according to our individual trading habits and preferences, is an important thing to have, and the particular one I'm talking about is SOOOO EASY to implement, so I just don't understand the unwillingness to allow us a choice, and force this system on those who don't want it.
Take it however you want, but that is my thought about it. >shrugs<
-- Smoov
Appreciate your input Smoov. Will definitely consider putting an option in the settings. As you mentioned, it should be easy to alter behavior to the way you describe on a per-user basis. It's a minimal amount of programming. (hour? maybe two?) So after some of the higher priority items are done it should be easy to plug in.