Japanese government bond yields fell to fresh record lows on Tuesday as Tokyo shares fell to a one-week low and generated bids for safe-haven debt, Reuters reported. The benchmark 10-year yield fell 3.5 basis point to a new record low of minus 0.085%. The 20-year yield dropped 5.5 basis points to 0.36%, also a fresh record trough, in reaction to a well-received 30-year debt auction. The bid-to-cover ratio, a gauge of demand, at the ¥800 billion ($7.08 billion) 30-year offering was a solid 4.21, compared to 3.04 from the previous sale in December. Dealers said the new 30-years were auctioned at relatively expensive levels but nevertheless attracted investor demand as the maturities still offered positive yields.