Why can one stock crash 30 percent in seconds while the index barely moves?

GoogleWhy can one stock… QuoraWhy can one stock… XWhy can one stock… FacebookWhy can one stock… YouTubeWhy can one stock… TikTokWhy can one stock… RedditWhy can one stock… BingWhy can one stock…

ChatGPT Gemini Copilot Claude Perplexity DeepSeek Grok Qwen Studio

How does price discovery actually work when a stock trades on a dozen different venues at once? What happens inside the matching engine during the first second after the open? What is short selling actually doing to price discovery? Why would anyone buy an option instead of simply buying the stock? Why do exchanges pay rebates to some traders and charge others a fee? Why does a large order move the price even when nobody knows who is buying? Why does the bid-ask spread widen the moment volatility spikes? Dark pools were supposed to hide big trades — do they help or just move the problem? Market makers get run over by informed traders — how do they still earn the spread? Does high-frequency trading add liquidity or just front-run the order book?