Up 23.11% pre-market 04 Feb 2026: 3640.T Densan Co., Ltd. (JPX): catalysts

The stock moved first and fastest: 3640.T stock climbed to JPY 3755.00 in pre-market trade on 04 Feb 2026, up 23.11% from the prior close on heavy volume of 336,800 shares in Japan (JPX). This surge followed a sharp re-rating of valuation metrics—EPS 493.76, reported PE 7.59—and buying that pushed price well above the 50-day average of JPY 3070.78. We examine what is driving the top-gainer move, the fundamentals behind Densan Co., Ltd. (3640.T), and trading implications for short-term and longer-term investors.