It depends on the circumstances. I probably take the largest positions in the most illiquid stocks of anyone on this board. I usually trade stuff that trades under 500k, and usually under 200k daily. I've been able to buy/sell as much as 20% of the daily volume on a stock and not move it "too much". You really have to quantify what you consider slippage to be. If i can sell 20k of something, and I only move the stock 30c within a 3 hour period, and complete my order, then I'm content. You have to also understand that you can't just send in a 30k market order and hope to get filled on the bid. You'll get raped. I almost never trade nasdaq, so I'll leave that part to someone else (though I have taken nas positions in stuff that only trades 10-30k shares a day and had 15k of it. It just takes a few days to unload. It depends on how fast you want to nuke the position on the nyse at least. Ideally, you should be selling into buying pressure, and buying into selling pressure. I fade overextended moves mainly. I usually am buying my first shares about 40c off a percieved bottom. I want to get about 70% of my position on before the stock reverses. This gets me in at the most ideal prices. You can use limit orders exclusively if you want. Once the bottom has been put in, I like to use some market orders to try and nudge it a bit..... See if there are more sellers or not. Since I am gonna sell into the buying pressure once the bottom is obvious, I just offer some out (really small) on the offer every nickle up at about a quarter below where i think the top is. Hopefully I can get out of 3-5k 200-500 shares at a time. Then I wait for bids. You have to sell when you can, not when you have to. Usually, if the stock is running away, somone will get desperate and just show 5-20k size bids.... Sometimes it's the specialist trying to push the stock higher to sell. The point is that you bitchslap the first bid you see. don't wait for it to move up or anything else... The only time I don't smack it immediately is when I don't have much left and I'm looking for better prices instead of liquidity. In that case, get in front of a large bid by a dime. Maybe you can get him to get a nickle in front of you, then hit him for the 10k. You just risked 1k shares to make an extra 1.5k. I think this is more detailed than you were hoping for. If you're trying to move 50k shares like your example in ge, I assume you can just send em in 10k at a time market style. I would think that 50k shares would move the stocka dime. There's tons of liquidity. The final thing to remember is to target liquidity. There's size on the halves. If you have 20k to sell and it's dropping rapidly, you can be a 3k offer at .15, and there's a k bid at .1, just offer 15k at the even. There's probably something there, and you'll get it before the specialist can hit it. Maybe you'll get lucky and have some bid leaners at .01-.06
