Coindesk has a great article on how to play Bitcoin's on the public markets.
1. BTX Trader stock WPCS International (NASDAQ) announced the release of its bitcoin trading application BTX Trader on 26th December. BTX Trader is touted as the first trading platform to allow users to execute orders on five of the most popular bitcoin exchanges. The software also lets users place stop-loss orders on trades, monitor real-time price feeds and use various charting tools.
2. SmartTrans (ASX) btcminer This mineral exploration company listed on the main board of Australia’s stock exchange is trading in its diamond drills for super-fast computers, as it revamps itself into a software services company with a subsidiary focused on bitcoin mining. The firm bought a bitcoin mining contract on 30th November through a joint venture it owns with Zhenya Tsvetnenko. According to SmartTrans, the contract had already generated about $150,000 of gross revenue in its first seven days. The contract is to run for 12 months in total. SmartTrans has a 50% stake in the joint venture with Tsvetnenko, which is a Hong Kong-incorporated firm called Digi8.
3. Overstock (NASDAQ) shopping key. The online retailer can’t stay out of the headlines as it announced both its decision to start accepting bitcoin payments and the stellar results from that move. It made $130,000 in sales from Bitcoin within 24 hours of accepting the cryptocurrency.
4. Bitcoin Investment Trust stock SecondMarket’s Bitcoin Investment Trust isn’t a publicly listed security, but sophisticated investors, which is its target market, can still buy units in it relatively easily. The trust is open to accredited investors as defined by the US Securities and Exchange Commission, which includes individuals with a net worth above $1m or an income exceeding $200,000 annually, among other conditions.
5. Zynga (NASDAQ) Farmville 2, by Zynga. Farmville 2, by Zynga. When the social gaming giant Zynga announced it would start testing bitcoin payments on 4th January, the news added 10 percentage points to its stock price to a high of $4.059 in intra-day trading.
More @: coindesk.com