I thought it would be easier to present the issue in a hypothetical: It's a slow and sunny afternoon, perhaps a Friday before a 3-day weekend. Many traders have already left their offices to get a head start on the traffic. You see a setup, a signal, a breaking headline -- something that requires your immediate entry. You realize not many have seen what you've seen, and you will be among the first to act upon it. For whatever reason (a chart formation, prior price action, etc) you feel pretty confident market X will probably move 3 pts, eventually, on this trigger. Your usual position size for this market and time frame, based also on your personal risk parameters, is 500 shares. But you see that there are at least 2000 shares available to lift within a certain range you consider acceptable for entry. Given the above, you now realize you have certain options to achieve the same result: 1. Buy 500 shares, target 3 pts (as initially determined) 2. Buy 1000 shares, target 1.5 pts (for the same result as 1) 3. Buy 2000 shares, target .75 pts (same result) (assume liquidity is adequate for exiting 2k shares without excessive slippage) 500 shares is your preset "comfort" level with this stock, but would doubling the size, cutting the target in half, and reducing duration of the trade be equivalent in risk? I'm guessing most of you would already say "take the 2k and go for original target of 3, if the market is going there it will go regardless" -- but let's not get into that for now. Right now, your initial trade intention is 500 x 3pts; your alternatives are 1000 x 1.5, 2000 x .75. Discuss.