2) They're worried the value of their options will drop out before they have the option to exercise them.
Check out Table 2 here, down on page 45:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2955455
It uses Square as an example. The headline valuation price from their E round suggests that a share of stock was worth $15.46. But later investors can have all sorts of preferences. Common stock, though, is valued at $5.62.
As people who were here for the last bubble know, this is exacerbated when valuations dip. I know a number of people who worked their asses off for companies that got sold for hundreds of millions of dollars. But the employees saw nothing, because investors get paid first.
They went public earlier this year. With burgeoning balance sheet they have to fire people:
https://www.businessinsider.in/Snap-hit-with-more-layoffs-pl...