Over the past 10 years, insiders at Inovio have sold more than $25 million in stock, according to the financial data provider Equilar. Last year, Dr. Kim was forced to sell about half his Inovio shares — causing the stock price to drop by more than a third — after he used his shares as collateral to borrow money and was caught in a so-called margin call, requiring him to immediately repay his loan. This year, following steep run-ups in Inovio's stock price, insiders have sold $3.8 million in shares.