At 8:20 AM EST this morning an unknown party began short-selling stock in Lockheed-Martin. (A short seller makes money when a stock drops.) Six minutes later, at 8:26 AM Donald Trump tweeted: "The F-35 program and cost is out of control. Billions of dollars can and will be saved on military (and other) purchases after January 20th." Lockheed-Martin is the designer of the f-35 and the lead manufacturer of the F-35 program. 

A substantial number of shares were short-sold just before the president-elect’s tweet, potentially netting the short seller millions of dollars in profit in a matter of minutes.

Insider trading
is stock trading for profit based on information known only to a small group of individuals with special knowledge about a company before it is revealed to the public. It is regarded in the United States as a serious crime. SEC Rule 10b5-1 provides that a person who trades on the basis of material nonpublic information and is aware of that information and that it will affect the value of a stock is guilty of insider trading if a profit is made from the trade.

The trade mentioned in this story has not been investigated by the SEC and whether or not it was coincidental remains unknown. However, the size of the trade and its proximity to Mr. Trump’s announcement should trigger an inquiry.