These sales are not normal sizes or even at normal times. Usually they do a good job of parsing these out over a period of time to not attract attention. These are pretty hefty sales even for these types of company's.
They know the end is near.
January 24th Alteryx Application Software.
1,150,000 shares at $66.75 for
$76,762,500
All in a day's work
https://www.finviz.com/insidertrading.ashx?or=10&tv=1000000&tc=7&o=-transactionValue