Snap says it’s raising $1B in convertible debt

>Snap said it will use the proceeds to cover operating expenses associated with running the business.

Perhaps someone can explain to me why anyone would take them up on this "oh you need a billion dollars to keep running? Sure we'll bet a billion on you" is how I see it play out in my head, which I can't see any sane investors doing.

Perhaps if it was 1 million, or 10 million, but a billion? Isn't that a massive gamble?