It is my understanding that the form 144 is "an intent to sell" form. One does not HAVE to sell on any particular day, or even at all. You are basically filling out a form saying you are considering selling. So there is no guarantee that even the 721,000 shares will be traded that day, or at all.
The flip side however, is another one of my understandings. I may be wrong on this but I am pretty sure I am not. One does not have to fill out the 144 form BEFORE actually selling the stock. I believe one has a 30 day grace period from the day you have sold your stock to when the 144 is filed. It seems stupid, but I saw "late" filed forms on numerous stocks around 2000 etc.
Again I may be wrong, and will admit it if I am. But with the above, the amount of shares that could be sold after the 16th may be MUCH higher than 721,000. And even if the above isn't true, it may be much higher.
Lets say I had 200,000 shares I wanted to sell. I would file my form 144 the DAY I wanted to sell, so it would minimize the affect on the stock price, thus costing me money!!!
The 144 forms are a VERY poor indicator of the number of shares that will be sold by insders.
I hope this came across as NON biased (long or short)
I thought it was just the oposite. Once you file for selling 144 stock you have 30 days to sell it. If you don't sell during the 30 days and if you still want to sell then you have to refile and get approved all over again. You certainly can't sell 144 stock and then wait 30 days to file
If you are not an affiliate of the issuer and have held restricted securities for two years, you can sell them without regard to the above conditions. (In other words you DON'T have to file a form 144!!!)