 Shares of MicroStrategy Inc. MSTR, -14.19 tumbled 14.4 toward a four-month low, in midday trading Wednesday, and has plunged 34.5 amid a three-day losing streak, as the software company-bitcoin play suffered from the recent plunge in bitcoin prices to a two-year low. The company, which makes enterprise analytics and mobility software, is also a bitcoin play since it acquires and holds the cryptocurrency as a treasury reserve. 