John Light knows a special kind of regret that's familiar to many others who got in early on bitcoin, the world's most popular digital currency.

Last year, Light moved to San Francisco to join the bitcoin revolution, and by this past March, the former online community manager didn't have enough dollars to pay his rent, but he have a lot of bitcoins. He ended up covering his monthly rent by selling some of his digital stash, but he quickly wished he hadn't. A month later, the bitcoins he sold for $30 each were worth more than $250. Today, a bitcoin goes for close to $900.

But there's a silver lining to his story. Light's March cash-flow problem has sparked a new business idea. He wants to open a bitcoin pawn shop, so that others can get some cash for their bitcoins without actually selling them. It's a business venture that plays into the idea – popular amongst bitcoin's true believers – that bitcoin is still in its early days and that it's still a bargain at over $900 for a virtual coin.

Light has teamed up with Carl Hilsz, a San Francisco pawnbroker, and set up a website called PawnCoin. Now, all he needs are some financial backers. The setup is pretty simple. You hand over your bitcoins to PawnCoin, and they store them in a "cold" bitcoin wallet that is not connected to the internet. A month later, you pay back the cash, plus a healthy 10 percent interest, or Light and Hilsz get to keep your bitcoins.

Last week, Light was pitching his idea to investors at Plug and Play, a Sunnyvale tech incubator. He describes as the perfect startup for the bitcoin bulls. Light, who has also started a weekly face-to-face Bitcoin marketplace in San Francisco known as Buttonwood, says a lot of his bitcoin friends like the idea. Many of them could have used a pawnshop "at one time or another" in their digital currency investing careers, he says.

But what if the whole bitcoin bubble should burst? Won't PawnCoin then go bust? "We have internal hedging strategies that we're working on right now to mitigate against the threat of a crash," Light says. He won't tell us what these hedging strategies are – "dealing with that risk is part of our proprietary secret sauce," he says – which is too bad. Stephen Gandel at Fortune recently tried to short bitcoin and found out that it was pretty hard to do.

You can't pawn your bitcoins just yet, but you can sign up to beta test the service. Light hopes to have the PawnCoin up and running by the end of March. Early interest seems to be coming from people who want to leverage what they own to buy even more bitcoins, he says.