In March 2000, Barron's reported that 51 Internet companies were burning cash so fast that they'd be broke by the end of the end of the year. The article (it's behind a seemingly unbreachable paywall) has acquired the reputation of having marked the end of the dot-com boom. The Nasdaq composite index peaked on March 10 at 5132, and by the end of the month was in a full-on collapse (as I write this, it's only at 3155, despite years of gains).
Related link (Bezos quotes Buffett and Ben Graham): Jeff Bezos on Leading for the Long-Term at Amazon
Amazon’s Growth Looks Like Walmart in the 1990s — But Even Better
Amazon’s Future Is Not in Selling Stuff — And That’s a Good Thing
Google’s Plan to Snatch Shopping From Amazon Is Working