The co-founder and CEO of Zerodha, an online stock trading platform, revealed on Monday that he had a mild stroke six weeks earlier.

The cause could be dad dying, lack of sleep, weariness, dehydration, or overtraining.

The finding is relevant because many under-40s have heart attacks. Kamath routinely shares his business and economic views on social media.

Along with his brother Nikhil, Kamath, 44, co-founded Zerodha in 2010 and serves as its CEO. As of February 27, Forbes estimates his net worth to be $5.4 billion.

On his website, Nithin Kamath says he started trading at 17. After borrowing money and "blowing up" his trading account, he worked in a call center for four years to repay it.