While I'm a newb to this forum and researching trading online, I've actually been goofing around with stocks for several years. I have one company where I buy a massive amount of stock, but I find selling in smaller portions to be wiser. I'm fully aware that I'm probably breaking lots of trader rules, but its my system, and it works for me.
This stock can have large swings within a day compared to many other companies. Usually there's a huge dip in the first 20-30 minutes, and come back or it can drift down to around lunch time, then repeak about 1-2pm. These two patterns are common on regular days. I've had days where it went up or down for no apparent reason. And of course it's crazy on days where there are big announcements.
Something to note is that the market capital for this stock is Billions, with the daily volume in the millions. So the 6000 shares I buy or sell only change the price $.10 or so. It's not uncommon to see trades of 30k or 40k shares in the volume bar.
When I buy in those dips, I already know I'm getting a discount so I'm not to worried about price. When I sell in big numbers the price will drop enough so my loss is more than the cost of the trade. Selling in small numbers only drops the price a little, and enough to validate the cost of that individual trade.
I think the key to your question is what is the market capital of that stock vs. your purchase? And how many shares are you buying compared to the daily share volume?