Global asset managers have been adding Chinese government bonds to their portfolios since the Iran war broke out, drawn not by yield but by their near-zero correlation with Western markets. Amid a global rout in sovereign debt since March that has sent benchmark yields soaring between 35 and 60 basis points (bps) in the U.S., Britain, Europe and Japan, yields on equivalent CGBs have declined 8 bps. The striking outperformance has caught the attention of real money investors - from sovereign funds and central banks to insurers - prompting a re-assessment of portfolio construction even as it pushed Chinese yields to the lowest outside Switzerland. Chinese debt is attracting investors with a "preservation mandate," offering regional portfolios a low-volatility counterbalance to riskier, higher-yielding assets, said Wei Li, head of multi-asset investments at BNP Paribas Securities.