Seems someone or some group is making lots of money seemingly knowing what Trump is going to tweet.  These are very large sums and seem to be the definition of insider trading.  From Vanity Fair.

“THERE IS DEFINITE HANKY-PANKY GOING ON”: THE FANTASTICALLY PROFITABLE MYSTERY OF THE TRUMP CHAOS TRADES

The president’s talk can move markets—and it’s made some futures traders billions. Did they know what he was going to say before he said it?

From the article:

But these wins were peanuts compared to the money made by a trader, or group of traders, who bought 420,000 September e-minis in the last 30 minutes of trading on June 28. That was some 40% of the day’s trading volume in September e-minis—making it a trade that could not easily be ignored. By then, President Trump was already in Osaka, Japan—14 hours ahead of Chicago—and on his way to a roughly hour-long meeting with China’s President Xi Jinping as part of the G20 summit. On Saturday in Osaka, after the market had closed in Chicago, Trump emerged from his meeting with Xi and announced that the intermittent trade talks were “back on track.” The following week was a good one in the stock market, thanks to the Trump announcement. On Thursday, June 27, the S&P 500 index stood at about 2915; a week or so later, it was just below 3000, a gain of 84 points, or $4,200 per e-mini contract. Whoever bought the 420,000 e-minis on June 28 had made a handsome profit of nearly $1.8 billion.