"We raised at a peak, but sold at a fraction of that," Unacademy co-founder and CEO Gaurav Munjal wrote. "I'm not going to dress these facts up."

Magna's investment in Yuma Energy has reached $87 million as the Canadian auto supplier increases its majority stake in the Indian battery-swapping firm.

Founded by a 20-year-old, Alteon is developing autonomous aircraft that hopes to harvest wind energy to stay aloft for several months.