Andrew Grauer got the idea for his first business back in 2006, when he was a sophomore majoring in Spanish at Cornell University and tore his lateral meniscus. Navigating the hilly and icy Ithaca, N.Y., campus on crutches was difficult. From his dorm room, Grauer started building Course Hero, an online library of class notes, essays and exam answers, mostly crowdsourced from other students.

“The lucky—and most important—thing that we got right was we focused on a real pain point,’’ says Grauer, 36. “Whether it was awkwardly raising my hand in class or walking to the library and through the stacks, there’s just a lot of inefficient, awkward, stressful moments.” Easier, sometimes, to stay in your room and get answers online. Senior Cornell computer science major Gregor Carrigan signed on as a cofounder, as did Grauer’s twin brother, then at Princeton, and his older brother, a Cornell Law student. Carrigan is still CTO, while Grauer’s twin went on to become a chemist and his older brother to practice law.

Through 2013 (the year Grauer landed on the Forbes 30 under 30 list), the team got by with about $2.5 million in angel and seed financing, including a chunk from Grauer’s father, Fred, a prominent angel investor and index fund pioneer, who still sits on his son’s board. In 2014, Redwood, Cal.-based Course Hero raised $15 million, at a $120 million valuation, to keep growing its core business, which by that point included tutoring and individual questions answered.

Then Grauer made what looks to be another lucky choice: he rode the Covid-19 wave of venture capital washing over edtech. Course Hero raised $80 million in the summer of 2020, hitting unicorn status, and another $395 million in late 2021—at a hefty $3.6 billion valuation (making Grauer’s estimated 20-25% stake worth as much as $900 million, at least temporarily, on paper).