Here's why business experts think $1 billion Casper's planned IPO could be a bust

· Online mattress company Casper, which filed for an initial public offering last week, could find it hard to complete its IPO, business experts told Business Insider.
· Wall Street has soured on unicorns, or startups valued at $1 billion or more, that lose money.
· Casper is losing money, thanks to high marketing,...