Masaya Yamasaki Nomura Securities Co.

The buy side says: “Yamasaki is always responsive to my questions.”

In March 2011, one week after Japan was ravaged by an earthquake and tsunami, repeat first-­teamer Masaya Yamasaki of Nomura Securities Co. issued a detailed assessment of the disaster’s impact on the sector — which plants were most heavily damaged and which were already resuming operations. For example, he reported that Kanagawa-­based semiconductor maker Renesas Electronics Corp. — a company not even among the eight he formally covers — had lost roughly half its production capabilities. “Yamasaki-­san is always a great source of information, especially reporting on technology supply chains,” reports one grateful client. The 43-year-old researcher slashed his earnings estimates and target price for Elpida Memory in August, at ¥548, reiterating a neutral rating he had had on the shares since January 2009, primarily on plunging prices of dynamic random access memory owing to an oversupply of computers. The company filed for bankruptcy protection in late February, and its shares closed that month at ¥7, a heart-­stopping 98.7 percent loss that pulled the entire sector into the red — it lost 1.5 percent over the period. —Ben Mattlin