Back in 2008, Tesla Motors' funds had dwindled so low, the company came within three days of having to declare bankruptcy. Only a last minute $40 million loan on Christmas Eve saved the company, as founder Elon Musk shared on Twitter. Musk was so committed to Tesla that he put all of his own money in, "didn't own a house & had to borrow money from friends to pay rent."
Even then, he still thought the company would likely fail — he just felt compelled to do all he could to save Tesla.
Now, it's fairly safe to say that few, if any, gambles have ever paid off so well.