We are always looking for the so-called tells in the market. These are when the really smart money tips their hand by buying or selling an abnormally large amount of stock or options ahead of an event.
Whether that event is an earnings report, new product introduction, or industry conference, the activity in the hours that preceded such catalysts can be amazingly predictive.
Such was the case of FedEx on Tuesday, as the shares opened higher, traded to $185 at their high of the day and then were hit with massive waves of block selling. It took all of 15 minutes to drive shares off their session highs. The stock closed at $181.41, down slightly, and this was absent any news in the company.
Sure enough, FedEx's quarterly results missed earnings and revenue estimates with CFO Alan Graf citing weak global economic conditions. The shares tanked after hours.
"Slowing international macroeconomic conditions and weaker global trade growth trends continue, as seen in the year-over-year decline in our FedEx Express international revenue," Graf said in a statement.
The stock was down more than 6 percent in premarket trading Wednesday, highlighting once again why what happens in the hours ahead of these events is so critical to follow.
— CNBC's Fred Imbert contributed to this report.