It goes without saying that investors in Japan should watch what the prime minister is doing. But with Yoshihide Suga now in power, it pays to follow a little more closely.

Shares in GMO Internet Inc., a tech conglomerate, jumped as much as 5.5 percent Thursday after founder and CEO Masatoshi Kumagai tweeted that he’d had dinner with Suga to discuss the prime minister’s digital reforms. Some of the GMO group’s other listed units surged by their daily limit, in expectation of its involvement in the shift to digital.

But eagle-eyed investors watching Suga’s movements could have spotted this opportunity earlier — and perhaps should more closely watch a daily press report of his movements for future trading clues.