U.S. Treasury yields have risen notably this summer as inflation concerns intensify, increasing investor sensitivity to bond-market volatility. Wharton professor Jeremy Siegel said current yield levels do not yet represent a major warning signal for U.S. stocks and that investors need not panic. He sees Federal Reserve Chair Kevin Warsh's speech on Friday, the 28th, at the Jackson Hole Global Central Bank Symposium as a possible bullish catalyst if Warsh explains which indicators guide the Fed's monetary-policy decisions, including 5-year inflation expectations, the federal funds futures market and other relevant data. Investors will also assess whether Warsh has discussed the Treasury's recent bond-market intervention with Treasury Secretary Scott Bessent. Siegel's view is more optimistic than it was in July, after the 10-year real yield edged lower, and he expects this week's Personal Consumption Expenditures (PCE) price index report to be relatively benign. He warned, however, that an uninformative speech could prompt investors to retest current yield levels. The 30-year Treasury yield recently breached 5%. Bank of America strategists said an explicit signal that the Fed could resume rate hikes if inflation fails to improve might lift September hike pricing from roughly 9 basis points to 12.5 basis points and raise cumulative cycle pricing from about 40 basis points to nearly 50 basis points. Barclays economists put the probability of such a signal above 50%. Morgan Stanley chief U.S. economist Michael Gapen expects Warsh to avoid clarifying the Treasury's intervention and to favor higher long-end rates as a way to tighten financial conditions. CME FedWatch currently shows a 58% probability of no September rate change, with the remaining probability leaning toward a 25-basis-point hike. The symposium runs from August 27 to 29, with Warsh scheduled to speak at 10:00 a.m. Eastern Time on the 28th, or 10:00 p.m. Taipei time, without a public question-and-answer session.