Tokyo stocks snapped a four-day winning streak Thursday, with the Nikkei briefly losing over 2 percent, on concerns that surging commodity prices may squeeze corporate profits and lead the global economy to slow down. The 225-issue Nikkei Stock Average ended down 508.36 points, or 1.89 percent, from Wednesday at 26,402.84. The broader Topix index finished 24.61 points, or 1.31 percent, lower at 1,860.08. On the top-tier Prime Market, decliners were led by marine transportation, insurance and service issues.