Kevin Warsh made his first big move as Fed chair, and the bond market has taken action -- but most investors missed it

This has been a history-packed year for Wall Street, with the Dow Jones Industrial Average (DJINDICES: ^DJI), S&P 500 (SNPINDEX: ^GSPC), and Nasdaq Composite (NASDAQINDEX: ^IXIC) hitting new highs and the largest-ever initial public offering taking shape. But the biggest eyebrow-raiser might just be the shift in power at America's foremost financial institution, the Federal Reserve.

On May 22, President Donald Trump's handpicked successor to Jerome Powell, Kevin Warsh, was sworn in as the new Fed chair. During his swearing-in ceremony, Warsh promised to lead a "reform-oriented" central bank -- and he's wasted little time implementing his very first significant change. Interestingly, the bond market has taken notice, but this change has mostly gone over investors' heads.

Kevin Warsh implements his first major Federal Reserve overhaul

Well before Warsh's confirmation as Fed chair, it was evident that his leadership style would differ notably from Powell's.

During his testimony before the Senate Banking Committee on April 21, he criticized the central bank's bloated balance sheet, insinuating that a deleveraging would get the Fed "out of the fiscal business."

Fed Chair Warsh has also been hypercritical of how policymakers think about inflation. He views price stability as "a change in prices such that no one's talking about it." Altering the very definition of inflation could afford the Federal Open Market Committee (FOMC) more flexibility in adjusting monetary policy, but also remove the transparency that Wall Street has become accustomed to over several decades.

But it's Warsh's first actual move as Fed chair that's moving markets. Although the FOMC kept interest rates unchanged at the June 16-17 meeting, Warsh axed forward-looking guidance from the meeting statement. This seemingly subtle action is having a meaningful impact on the bond market.

The new Fed chair can impact interest rates without lifting a finger

The inclusion of forward-looking guidance in FOMC statements has been commonplace since 2003. Although policymakers weren't technically bound to follow their guidance, these statements provided transparency and predictability that the bond and equity markets have come to rely on.

The removal of forward-looking guidance by Kevin Warsh introduces a degree of speculation that simply hasn't existed for much of this century.

In the bond market, we've witnessed a decisive uptick in Treasury bill and bond yields, indicating that bond prices are being depressed. Given that U.S. inflation hit a three-year high in May, driven by the ongoing Iran war, the lack of forward-looking interest rate guidance has encouraged bond traders to push up yields.

Neither Warsh nor the FOMC has altered the federal funds target rate, but we're nevertheless seeing evidence of higher yields translating into potentially higher borrowing costs.

The Fed chair's first big move may spell trouble for the second-priciest stock market in history, dating back to the early 1870s. If Warsh can influence interest rates without officially altering the FOMC's federal funds target rate, higher lending costs could weigh on the stock market's No. 1 catalyst: the artificial intelligence (AI) data center build-out. If AI infrastructure expansion slows or becomes impeded as Treasury yields rise, it would likely spell the end of Wall Street's historic AI-driven rally.

Sean Williams has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.