Oscar Health, Inc. co-founder and insider Mario Schlosser sold 286,988 shares on June 23, 2026 at $28.95 per share, for total proceeds of about $8.31 million. The transaction was reported as executed under a pre-scheduled Rule 10b5-1 trading plan, which is set up in advance to allow insiders to trade on a fixed schedule and reduce concerns about trading on non-public information. This matters because sales by senior insiders can draw attention, especially at multi-million-dollar sizes, since insiders typically have deep knowledge of the business and its operating trends. At the same time, a 10b5-1 plan can make a sale less informative than a discretionary trade because the timing and amount are usually determined earlier. Over the past 30 days, the only reported insider activity at OSCR is this single sale by Schlosser. With no additional recent insider buys or other sales in the same period, investors have limited ability to read this as part of a broader pattern, and the filing points to a routine, planned transaction rather than a change in insider sentiment.