While stock investors have pushed AI-related shares to repeated highs this year, debt markets are telling a more cautious story as newer AI infrastructure companies find themselves paying significantly elevated interest rates to borrow money. Applied Digital, a data center builder, sold $2.35 billion of debt in November at a 9.25% coupon -- roughly 3.75% above similarly rated companies, or about 70% more in interest costs. The pattern has repeated across several deals. Wulf Compute, a subsidiary of Bitcoin-miner-turned-data-center-operator Terawulf, raised $3.2 billion in mid-October at 7.75%, well above the 5.5% average yield for similarly rated issuers. Cipher Compute sold $1.7 billion in early November at just over 7%. CoreWeave, which rents data centers and installs computing systems for companies like OpenAI and Meta, raised $1.75 billion in July at 9%. The company's bonds have since fallen to around 90 cents on the dollar, pushing the effective yield above 12% -- nearly double the average for companies at its single-B rating level. "We just have to be much more pessimistic and not buy into the hype," said Will Smith, a portfolio manager at AllianceBernstein. Construction delays and uncertain demand for AI computing power remain key concerns for lenders who, unlike equity investors, have no upside beyond getting their principal back.Read more of this story at Slashdot.