The core claim is substantially supported by Reuters' article 'ネットフリ第1四半期は売上高が予想上回る、会長退任発表で株価約8%安', which directly states that Netflix reported stronger-than-expected revenue and that founder Reed Hastings said he would not seek re-election to the board. Reuters also says the stock dropped about 8%, not clearly 'over 9%'. Netflix's official pages 'Netflix - Financials - Quarterly Earnings', 'Netflix - Netflix to Announce First Quarter 2026 Financial Results', and 'Netflix - News & Events - Investor Events' corroborate that the Q1 2026 earnings event occurred on the stated date. So the statement is likely true in substance, especially regarding better-than-expected earnings and Hastings stepping down, but the precise magnitude of the stock drop appears overstated based on the evidence gathered in this run.