Powell is again serving as Acting Chair of the Federal Reserve, marking the second time he has held this temporary position during his tenure, and he may also become the shortest-serving Acting Chair in U.S. history!

Although Waller successfully passed all legal procedures through the Senate, Trump did not sign the appointment immediately during his visit to China,
and Waller still has some personal assets to divest, which led to him not officially taking over as Fed Chair on May 15 as scheduled. Currently, it is expected that Waller can smoothly assume the role within a week.
According to convention, the Fed internally votes Powell as Acting Chair. Here, a detail needs to be noted: remember that last month Powell explicitly stated in a public speech that if Waller cannot take office smoothly, he will become the Acting Chair, which is a right granted to him by U.S. law.
Actually, this detail is very important. Knowing there was a voting agenda, Powell still remained confident he would become the Acting Chair. Powell appears to have very strong confidence, and this confidence comes from support within the Fed colleagues.
Based on the Acting Chair vote, out of 7 board members (including Powell), Milan voted against, Bostick abstained, and the other board members, excluding Powell, have 4 supporters. This is Powell’s backing.
From this detail, it can be inferred that if Powell remains at the Fed, his policies and opinions will have a significant guiding influence on the FOMC. At least four board members support his views, which makes the shadow chair position more defined.
A new chair with an unstable foundation, and with Milan, who is clearly supported, replaced by Waller; another, Bostick, is obviously a swing voter. One is an 8-year veteran chair, an old colleague and partner. It’s easy to foresee that after Waller takes office, it will be difficult for him to fully implement his agenda, likely being constrained by Powell, and the policy will inevitably be “lame” in the short term.
A little science tip:
There have been three clear cases of interim chairs in U.S. history. The first was Greenspan in 1996, who served for 109 days.
The second was Powell himself in 2022, because his first term had expired, and the Senate reviewed and confirmed whether to reappoint him, serving as interim chair for 107 days.
The third, surprisingly, was also Powell himself. However, this term is not expected to be very long, and it is likely to become the shortest-serving interim chair in Fed history!