One suggestion. It would be nice if I could have multiple orders outstanding on the same bitcoins. Then auto-cancel the order after one fills. This provides more liquidity to the exchange as well.
Often times I would like to put a bid in on a couple stocks and would be OK with either one filling.
They started adding this - I was one of the few accounts given that functionaility for a while (it seemed to work fine but never displayed the correct reserved funds). But apparently some idiot on irc managed to convince them it doesn't add liquidity so they removed it (with some people it won't add liquidity, with others it will - but for very very few will it remove liquidity, so overall liquidity across all securities DOES increase as a result). The main increase comes from those trading on multiple sites - who can move more funds in if some orders get filled but don't want to cover every order 100% all the time when most orders only have a small chance of being filled in any given week (many assets there's often days or weeks without any significant trading volume - making it hard to justify leaving funds there backing just an order on that asset).
The lqiudiity it adds could be improved if instead of totally cancelling orders it just scaled the quantities back to match available funds. This avoidins the situation where I have enough cash for 199 shares, place orders for 100 on each of 2 different securities and when one fills the other gets totally cancelled - which is one of the few situations where it CAN remove liquidity, though only due to bad planning by the person placing orders.
If added back in, it should really be an optional feature - not everyone wants to use it.
