THE Shenzhen markets seesawed yesterday in moderate trading as investors remain cautious about future developments. Both markets did manage to edge up, however, perhaps bolstered by the buying spree in Shanghai. The CLSA Shenzhen A Index was up a modest 0.73 per cent to close at 2,837.36. Trading in the B market was exceptionally light, with the Shenzhen B Index closing up 0.45 per cent at 1,241.58. A wave of mass speculative buying hit the Shanghai A market yesterday. Investors bought heavily on news that the securities committee was finally going to resolve the issue of state-owned bonus shares. A decision might be available today, the committee said. The CLSA Shanghai A Index shot up a dramatic 12.27 per cent to close sharply higher at 6,996.96. The B market remained relatively quiet, however, with the CLSA Shanghai B Index closing up 1.52 per cent at 1,007.63. All B share and composite indices are based in US dollars.