Millionaire hiding envelopes of cash around San Francisco

William La Jeunesse reports from Los Angeles, California

A successful anonymous real estate investor in California's Bay Area is having fun with his disposable income: He's hiding envelopes stuffed with cash for strangers to find.

He offers clues to the whereabouts of the envelopes on Twitter under the handle @HiddenCash.

"People complain that the price of real estate here is pretty high and I have benefited from that," he told ABC News over the phone. "I wanted to do something fun for the city of San Francisco, something that would get people excited."

And excited they are.

"People like to be right, to find clues and follow something to the end. Find something that nobody else has found yet," said Matt Burkurt of San Francisco, who climbed up an abandoned bulldozer to find one of @HiddenCash's envelopes.

His clue was: "Stand on top of the Caterpillar that's close to the water."

The anonymous cash-hider has given away nearly $4,000 since Thursday night, the majority of it in $100 increments. He hopes to expand his treasure hunt to New York City and Los Angeles soon — and plans to keep hiding the cash "indefinitely."

"I'm giving right now about a thousand a day," he said. "For me, that's definitely manageable. I know that for most people it's more than they earn, but I'm in the top 1 percent. I can keep doing this."

He told KTVU that he gives a lot of his money to charities, including the San Francisco Food Bank, and that the treasure hunts exist simple to "put a smile on someone's face."

He hopes his generosity will inspire others to pay it forward.

"If people need the money for themselves, that's fine. But if they can share it that with others, that would be great," he said. "I've heard some heart-warming stories from people donating to charity and sharing it with other people who are less fortunate."