San Francisco's Coinbase was recently reported to have made $1bn in 2017, outstripping its revenue forecast by 66%, or $600m. Although its success has piqued the interest of venture capital investors, the company continues to operate privately and will not permit its stock to be traded by brokers on secondary markets.

The December launch of Bitcoin futures in Chicago initiated a massive influx of new registrations, as Bitcoin prices went through the roof and people were anxious to get in on the deal. On one day alone in December, Coinbase had 100,000 new users registering on the platform, reaching a total registration of 13 million. Although the Bitcoin bull run lasted only a short time, Coinbase made a massive profit out of the increased trading activity. Users wishing to trade currencies via Coinbase's GDAX exchange pay fees for converting fiat money to crypto, which go into Coinbase revenues.

As well as buying crypto, some investors want to buy shares in Coinbase, but the private shareholders have been instructed that selling their shares to an outsider constitutes a breach of company policy. The company has raised money through previous rounds of investor funding but is unlikely to need to do that again, meaning that no-one will be able to buy shares in Coinbase unless the company goes public.