CEOs and other officers typically have schedules to sell stock, precisely to avoid a situation where selling lots of shares might be interpreted as being a sign.
Executives at public companies are often subject to lock-up periods when they can sell their stock. That is likely the case here, and nothing can be inferred from it.
That's not <i>'a lot'</i>. Selling 0.01% of his FB stocks in a day is nothing. If he kept that pace whole year he would have sold 3.5% of his FB stocks.<p>Some people are just bad with numbers and understanding them in context.