You can't really answer that question until a startup goes to raise more money and can't get a favorable term sheet. So its kind of like the uncertainty principal. And startups, knowing that funding has been pulled back, are working harder to not have to even ask the question (they cut costs, try to boost revenue, extend the runway they have past this current period)
Also called a "down round"
Which means the most recent investor's investment is underwater, but not necessarily the company as a whole.
That and usually all employees' stock options when talking liquidation preferences, with some of them knowing and some not. At that point prepare for talent bleed until either some very good plans and news or a long, slow death.