One early Wednesday morning last July, when the subprime mortgage meltdown first began to rock the markets, I found myself sitting with investing legend Julian Robertson in the cabin of his Gulfstream V jet in Auckland, New Zealand. We were en route to one of the two world-class golf courses he has built in the island nation. But his mind was on the markets halfway around the world. As the flight crew prepared for takeoff and his wife Josie and their other guests found their seats, the 75-year-old billionaire used his mobile phone to check in with his office back in New York. "How are the subprime positions looking?" he asked excitedly. "Mm-hmm. Wonderful."
He hung up and turned to me. "My gosh, this has been the most extraordinary period of my career as an investor," he said. The big short bet he had been riding - by owning credit default swaps on subprime debt - was suddenly paying off richly as values plummeted. As his mouth turned up in a half smile he added, "I think this is the best month I've ever had. It's got to be."
Not bad for a "retiree" who was written off by many as washed-up when he stepped away from managing other people's money almost eight years ago.
As I learned in a series of conversations with Robertson over the past six months, the man once known as "The Wizard of Wall Street" for the incredible success he had running his hedge fund firm Tiger Management has been on a magical run while most of the world wasn't watching. According to returns provided by Robertson exclusively to Fortune, he earned a stunning 76.7% return in 2007 managing a portfolio of his own money. That rivals his best years running his flagship Tiger fund in the 1980s and 1990s, when he was an undisputed Master of the Hedge Fund Universe and grew Tiger from $8 million at its launch to over $22 billion at its peak in 1998.