MicroStrategy is taking advantage of its surging stock price to sell a $1.75 billion issue of convertible bonds and plans to use the proceeds to buy additional Bitcoin. After the close of trading Monday, MicroStrategy said it plans to issue convertibles with an interest rate of 0% in a private offering to qualified institutional investors under rule 144A of the Securities Act of 1933. The deal will likely be one of the larger ones in the convertible bond market this year.