SoftBank Group was able to reduce underwriting fees for yen retail bonds for the first time in a decade, underscoring the market’s perspective that its credit quality is improving.

Billionaire Masayoshi Son’s firm paid brokerages ¥1.10 per ¥100 to underwrite ¥550 billion ($3.5 billion) of seven-year notes for individual investors, according to a company filing. That was a decrease from the ¥1.25 rate that it paid on its retail bond sales since 2014, including its most recent deal in March, data compiled by Bloomberg show.

Debt rating firms have raised SoftBank Group’s grade as the Tokyo-based company’s earnings from investment begin to stabilize. Japan Credit Rating Agency in April lifted the firm’s debt score to A from A-, its first upgrade in more than a decade, while S&P Global Ratings raised SoftBank’s rating to BB+ from BB in May, still one step below investment grade.