<OT>Joseph, no broker will be able to avoid giving you partial fills through ISLD - that's the nature of the beast. ISLD orders can be atomized by getting crossed internally for partial fills, or being Snet by an MM f.ex.
Ordinarily, market orders have preference in order of execution, over limit orders. However, in reality, you will often get executed faster with a limit order.
The reason is that your market order is handled by routing software at your broker - in the case of Datek f.ex., your market order will go to an MM. By nature, MMs (contrary to what you read on this thread) are slower to fill orders - the only time an ECN is slower, is if it doesn't have the liquidity on a given stock. MMs have automatic or electronic execution of their minimum size displayed - f.ex. 100 shares. And if you have a market order, that will take preference (w/ a DOE broker, you have the option of doing a market SOES, which should be the fastest - if you are the first in line, i.e. you sent the order first ahead of others). However, beyond that, an MM can, and does take his sweet time in giving you a fill (unless the market is turning against you, in which case you'll get filled extra fast, and immediately show a loss<g>). MMs have 17 seconds in which they can watch the market and how the orders stack up - during this time, they can pick the worst scenario - if you are buying, and they see a lot of sell orders, you'll get filled; if on the other hand, there are a lot of buy orders, he will hold your order for 17 seconds, not fill you, and raise the price (he has 17 seconds to execute you, or he must refresh his quote - in practice, MMs break this rule often, and I see outrages happen practically every day). So, if you send out a market order, especially if you are not the first in line, you might get partials from an MM too - he'll give you his minimum 100 shares, then he'll walk the price up, and fill you for the rest at the top of the market price. Similiarly with sell orders - you'll get filled at the bottom.
Now, a limit order is a different animal. Theoretically, it is supposed to get filled only after a market order. But, because most of the time your limit order will be sent by Datek to its ISLD ECN (assuming your limit order is marketable) - you have a good chance to get crossed within ISLD virtually *instantly*. This of course depends on liquidity etc. ECNs accept only limit orders. Now, if your limit order is the inside quote on ISLD (or any ECN), you may not get crossed internally, and so ISLD will represent you on LII. If your order in addition is the inside market order (in addition to being the inside ISLD order), you have a chance to be hit by an MM, f.ex. or still get crossed internally on ISLD if an opposing order appears.
As you can see, there are very good reasons, why limit orders are often faster than market orders, never mind what the rules say.
As to CyberTrader - it is a good platform, but I think for someone in you situation (and for 99.9 traders out there, IMO), you should rather look into CyberX.
Morgan |
