"Lockup" is an investment term. When a company has an IPO (Initial Public Offering, which is the day they become publically available for stock trades), the big shareholders and company employees who are invested ahead of the IPO are "locked" from selling their shares for a certain number of days. This isn't required, but most companies having an IPO end up having a lockup period set as well.
In regards to this headline, it just means that the initial investors and big shareholders are now free to sell their shares, which they are apparently doing in droves!
It's as simple as swiping down on the screen. I agree it's a little under-sensitive if you try to swipe down from the circle with the icon at the bottom. But you can swipe down from anywhere on the screen and it will decline the call.