Quote from inandlong:
For example IYR which was on your watch list. It has traded 7900 shares today. My usual entry is 2-4K shares and then build from there. I don't want to be a significant percentage of any market. And there is a 25 cent spread there right now.
A number of the ETF's trade very low volume that way.
The traded volume has no so singificance, because even no trade is done as underlying index is going up or down, then specialist has to chnge bid/ask in the right way.
You have to watch underlying index value (like NLR.X for IYR) to know where is actual index price and then send Limit order close to index value. 2-4K shares is no problematic to receive fill.
When I enter trade +/- 5 cents from current index value is OK for me to enter trade.