100 share trades are for the most part meaningless. Unless you believe that 'technical analysis' and MM manipulation stuff. I wonder how many people have read the tea leaves wrong on the two occasions (about a month back) that I put through 100 share buy orders to test an account.
Several people have posted the mm code. A 100 order is "I need shares". I haven't watched chart today but I've seen etmm put out the 100 I need shares signal before- which I think is the most desperate mm signal. For there are other mm I need shares signals which are coupled w other things. Maybe somebody can post what those 100,200,300,400,500 etc signals mean again.