NEW YORK/LONDON (Reuters) – Seven years ago, Marshall Hayner gave his grandfather one bitcoin, worth about $30. On the paper wallet he fashioned to commemorate the gift, the US entrepreneur and software developer wrote: “Do not open until $100,000.”

It made Hayner’s grandparents laugh, and indeed bitcoin has not come anywhere near that level. But it is worth more than 200 times what it was in 2011 when Hayner made the gift.

Investors who took a chance on the fledgling currency and stuck with it have been on a rollercoaster ride – but are optimistic that they are still onto a winner.

“I have seen these run-ups and drops in bitcoin and I did not even flinch,” said 34-year old Mr Hayner, who started mining bitcoins in 2009 when the granddaddy of all cryptocurrencies was worth nothing.

“I believe in this technology. I really believe that bitcoin is the next digital gold,” he said

Bitcoin yesterday celebrated ten years since Satoshi Nakamoto, bitcoin’s mysterious founder, released a whitepaper outlining the need for an internet currency that could be used as payment without going through a third party like a bank.

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