Shark Tank investor Kevin O’Leary is encouraging founders to reject Silicon Valley’s hustle culture. 

In a recent Instagram video, O’Leary called out the notion that working 18 hours a day is a badge of honor. He labeled the work schedule as “stupid” and a misunderstanding of what real high performance looks like. 

“The worst advice I hear young founders talk about all the time is that they want to work 18 hours a day,” O’Leary said in the Instagram video. “How stupid is that? You’ve got to get some sleep, you have to eat well and you’ve got to stay focused. That’s how you’re successful.”

O’Leary’s remarks speak directly to a generation of founders caught between protecting their health or sacrificing it in search of success. The pressure intensifies in light of extreme work cultures like “996,” a 9 a.m. to 9 p.m., six-day-a-week schedule now romanticized in some corners of the tech industry. The 996 concept originated in China; the country banned the work schedule in 2021. In recent years, it has gained popularity in Silicon Valley. AI startup Rilla, for instance, told potential new hires that they would work more than 70 hours a week if selected for jobs.

Established tech giants are also demanding more hours from workers. Last year, Google co-founder Sergey Brin told employees working on Gemini AI that they should be working at least 60 hours a week — all in person. Meanwhile, Glassdoor users reported that some Meta employees have to work between 60 and 70 hours a week, including weekends. 

Against this backdrop, O’Leary’s message is that it is counterproductive to work constantly. Instead of bragging about sleepless nights, O’Leary says founders should rely on basic wellness habits to achieve success, like exercising regularly. 

“This idea that you don’t get any sleep, as if it’s good for investors, is sheer stupidity,” he said in the Instagram video. “You have to get sleep, you have to be rested. You have to eat well, and you have to get some exercise. That’s how you optimize.” 

O’Leary added that the best time to make decisions is right after waking up, when the mind is clear, and the body has peak energy. He said that he doesn’t invest in startups where the founder looks unwell. “If you show up looking half-dead, I’m not investing,” he wrote in the Instagram video caption. “You’re not a hero, you’re a liability.”

His tone is a notable shift from earlier messages. In a 2024 post on X, O’Leary wrote that “if you want to succeed in business you have to work 25hrs a day” because there is always someone out there ready to outwork you. It’s unclear why O’Leary has changed his perspective. 

According to Harvard Medical School, “toxic productivity” is an obsessive tendency to be productive and always on at work. The phenomenon can take a toll on well-being, causing chronic stress, anxiety, depression and insomnia. 

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