The investment-grade bond market faces a busy September, but demand for corporate debt suggests anxiety about heavy supply may be overblown, according to Kelsey Berro, a portfolio manager at JPMorgan Asset Management.Issuance expectations are in a wide range of $175 billion to $250 billion, Berro said in an interview with Bloomberg Television on Monday. Credit portfolio managers have indicated that even $250 billion in supply “is not really an issue,” though uncertainty about the final figure is complicating preparation across the market, she added.The spread in forecasts is itself a source of tension. A $75 billion gap between the low and high ends of estimates makes it difficult for portfolio managers to position ahead of what is historically one of the busiest issuance months of the year.US blue-chip bond sales set a third straight monthly record in August, continuing the market’s fastest pace of issuance as spending on the artificial-intelligence buildout fuels corporate borrowing. Investors are getting pickier about what they’ll buy, and at what price, as the borrowing frenzy takes its toll. Some companies looking to finance data center projects are increasingly turning to junk bond investors to help them raise billions of dollars, even for debt that is investment-grade. With two weeks left to go, August supply has already reached $157 billion, boosted by Alphabet Inc.’s $25 billion offering, and other large deals from AbbVie Inc. and Advanced Micro Devices Inc.Despite the supply concern, demand has kept pace with record issuance throughout the year. Retail demand for investment-grade bonds has already exceeded the full-year total for any year back to 2010, according to high-grade flow data cited by Berro.“While there has been record supply, there has also been record demand,” she said, pointing to the dynamic as a key reason why September’s heavy calendar may prove more manageable than feared.If September supply is absorbed without disruption, Berro warned that sidelined investors could move quickly. “There will be a rush into the market,” she said, adding that any sign of stability would likely draw buyers back in force.Companies have already borrowed more than $410 billion for data centers and other AI investments this year, according to data compiled by Bloomberg News.More stories like this are available on bloomberg.comPublished on August 25, 2026