All three major indexes on the New York Stock Exchange closed lower. The shift came as Kevin Warsh, Chair of the U.S. Federal Reserve, raised the level of caution on inflation, making the possibility of a September base rate hike a key variable for the market.

On the 28th (local time), the Dow Jones Industrial Average finished trading at 53,559.99, down 9.45 points (0.02%) from the previous session. The Standard & Poor's (S&P) 500 index closed at 7,711.76, down 19.23 points (0.25%), while the tech-heavy Nasdaq Composite ended the session at 26,402.42, down 138.93 points (0.52%).

■ Chair Warsh Delivers First Jackson Hole Speech Since Taking Office... "Difficult to Judge Underlying Inflation Has Improved"

The market's focus this day was on the Jackson Hole Economic Policy Symposium held in Wyoming. In his first Jackson Hole address since taking office, Chair Warsh said that while recent inflation data had come in better than expected, it is difficult to conclude that the underlying inflation trend has improved meaningfully.

In particular, he suggested that if there is no confidence that prices are moving toward the Fed's 2% target at a sufficient pace, further responses would be necessary — remarks the market interpreted as a hawkish signal.

■ Odds of September Rate Hike Rise from 35% to Mid-to-High 50% Range

The interest rate futures market moved quickly as well. According to CME FedWatch, the probability of a rate hike at the September Federal Open Market Committee (FOMC) meeting rose from around 35% before Warsh's speech to the mid-to-high 50% range afterward.

In the bond market, the yield on the policy-sensitive 2-year U.S. Treasury jumped to the 4.3% range, reflecting the increased likelihood of a rate hike. Rising Treasury yields weighed on technology stocks, which face relatively heavier valuation burdens.

■ Nasdaq Falls 0.52% on Semiconductor Weakness... But Posts Weekly Gain for First Time in Three Weeks

Weakness in semiconductor stocks also dragged down the Nasdaq. Nvidia fell more than 4%, and Marvell Technology dropped more than 10%. In contrast, some large-cap tech names such as Alphabet and Apple rose, cushioning the index.

On a weekly basis, however, all three major indexes rose. The S&P 500 gained about 0.5%, the Nasdaq about 0.9%, and the Dow about 0.5%, marking their first weekly gain in three weeks.

■ Attention Shifts to Employment and Inflation Data Ahead of September FOMC

The market's next focus is expected to shift to employment and price data scheduled for release ahead of the September FOMC meeting. As Chair Warsh did not specify a timing for a rate hike, upcoming economic indicators are expected to significantly influence the actual monetary policy decision.

[This article was written with the assistance of AI. It is reference content based on publicly available materials and market information, and is not intended to recommend the purchase, sale, or investment in any specific stock. Stock investing carries the risk of principal loss, and the final investment decision and responsibility rest with the investor.]