"Given high demand, we upsized our $MSTR offering of 0% convertible bonds due 2029 from $1.75 billion to $2.6 billion, including a $400 million greenshoe option, and priced it at a 55% conversion premium." @michael saylor

He's extremely bullish, effectively borrowing money at 0% interest. He offers investors the chance to convert the bonds (debt instruments) into company shares at a 55% premium. Investors are also optimistic about the stock's potential to rise, which has driven up demand. The greenshoe option acts as a backup plan to accommodate any additional demand if needed.