Private companies typically don’t like to comment on their supposed valuations. But what many of them are willing to discuss is the effect that those big valuations have had on their reputation, their employee morale, their future, their entire business. A $1 billion valuation means different things to different executives.

Our Unicorn List will involve tracking these fast-growing, highly valued startups. We reached out to the founders and CEOs and asked a few questions. What does having a billion-dollar valuation (or higher) mean to you and your company? How does it change the way you operate? Is it a sign of success, or added pressure? We also asked about challenges and roadblocks along the way. What was your lowest moment or biggest obstacle on the path to where your startup is now?

We even asked them, if they were willing, to tell us about the moment when they closed the round that resulted in their most recent valuation, and where they were, and how it felt.

Here are some of the most colorful responses.

And be sure to read the cover story of our new issue: The age of unicorns.