No. It's an uncertain Bayesian world. You evaluate on the probabilities. Given a 20% chance that tweet is true, then what is the S&P worth now? Less. So you

No. It's an uncertain Bayesian world. You evaluate on the probabilities. Given a 20% chance that tweet is true, then what is the S&P worth now? Less. So you act. You don't sit around waiting to find out...