Martin Shkreli, the disgraced pharmaceutical executive, continues to run his company from prison with the help of a contraband cellphone, The Wall Street Journal reports. Shkreli was sentenced to seven years in prison last year for defrauding investors in his hedge funds and for manipulating the stock of his pharmaceutical company. The company, Phoenixus AG, brought to light the industry-wide practice of hiking up the prices of rare drugs. Shkreli jacked up the price of one HIV drug from $13.50 to $750. The so-called “pharma bro” recently fired his handpicked chief executive over the phone while he was on vacation, according to a source familiar with the exchange.

Shkreli plans to emerge from jail richer than he entered. According to his own calculations, Phoenixus could be worth $3.7 billion by the time he is freed in 2023. For that to happen, Shkreli plans to acquire more rare drugs in various stages of development and invest in ambitious research and development. The incarcerated executive reportedly spends his time reading pharmaceutical research on the inmate computer lab or on his phone.