partial fills

Discussion in 'Trading' started by mockingbird, Mar 15, 2002.

  1. Using CyberTrader, is there any way to avoid partial fills? Or what is the best way to handle them? Trying to trade QQQs in lots of 2000.
  2. Magna

    Magna Administrator

    The short answer is no. I'm surprised you're having that trouble as the Q's are so liquid, unless you are always bidding (while going long), or offering (while selling/shorting). If that's the case, you will probably have to eat the spread -- which is minimal with the Q's -- and start hitting the bids and lifting the offers.
  3. Magna, thanks, this is good info; sorry to be so clueless, but I am also confused about the following point: are partial fills possible on limit orders or only on market orders?

    I had considered what you said about lifting the offer and hitting the bid, I wondered if using limit orders this way would be one way to avoid partial fills.

    Just as background info, I am trying to get an idea what fills to expect -- I have just opened my account, I have been making money consistently with the *simulator* and before I trade for real I am trying to picture in my mind how the real fills are going to differ from the simulator so I can plan how I will react.

    I know there is going to be slippage and partial fills, I just don't know how much to expect.

    Also I hope one thing you said is true: that I should not have much trouble snagging 2000 shares without getting partial fills. I realize QQQ is a very liquid stock and that's why I picked it to trade.

    Any more comments are very welcome!
  4. A market order has to be filled but I've been filled many times by partial say I want 1000 I'll get 200 at 56.49 than the rest at 56.55

    Robert Tharp
  5. I'd recommend from personal experience to do smaller lots, 100-200 when you move from the simulator to active trading.

    Because the Q's don't make very big moves, paying up for the spread (which is often necessary in order to catch the corresponding NQ move, which can be very very quick) can add up quite fast...say your average move is 0.10, but you average 0.3 in spread costs round trip (and I think that may be a little conservative)...that just increased you need to be right by approx 30% more on the average.

    Just my 0.02
  6. Eldredge


    If you trade QQQ on Island and hit the bid or lift the offer with limit orders, I don't think you will see much slippage or partial fills at all. If you go .01 outside the spread you will almost always get an instant fill at or better than your limit I think - that is my experience (I don't tend to chase a fast moving market very often though).
  7. Magna

    Magna Administrator

    Not sure what you mean here, as they are only possible on limit orders. As in Robert's example, market orders will never partial and always get filled although your order may well be divided into smaller lots at various prices.

    Not necessarily, really depends on the liquidity at the inside and how fast the market it moving. You might also consider Eldredge's suggestion: "If you go .01 outside the spread you will almost always get an instant fill at or better than your limit." The only thing I would add is that if the Q's are really ripping .01 may not be enough, just depends on liquidity at that moment and how fast you are.

    The simulator is a good way to get a feel for the software, but a horrible way to get a feel for fills. Unfortunately the only way to do that is by live trading. Let's say the current market is 35.22 x 35.24 and you want to go long. If you put in a bid on the simulator at 35.22 you will almost always get filled, yet in real trading, unless the market is coming in, you probably won't get filled, or maybe you'll get a partial depending on whether anyone is ahead of you. That's why I said, if you're going long and want to avoid partials, you will probably have to eat the spread and lift the offer (assuming there's enough liquidity there). Fortunately with the Q's the spreads aren't too punishing.

    Anyway, hope this helps.