Given current history, the Feds I guess. President is powerful, but he can't just dig an economy out of recession (which seems to be the times when we have huge swings, for the sake of change). Even if he could, the methods are so unpopular that you basically doom your campaign. Only a lame duck could afford that.

That's a part of why the Feds levy a lot of independence. In this case, what the people want isn't always the best for them.

The Feds are not one person, and they cannot affect as much as the President. The main board is 12 members, with several others rotating in and out, and by statute they have congressional oversight. The members also have to answer to the regional banks their section oversees, so there is significant checks and balances.

Several of the powers I listed above for the President are absolute (well, up to impeachment, but I doubt any President would be impeached for trade war tanking of the economy.). There are many more powers a President can invoke, such as nationalizing industries, seizing production, halting trade, all under various War Powers Acts, which the President alone can invoke. Of course after the fact Congress has some oversight, but not much.

Last Trump term he declared all sorts of things were national security issues then applied tariffs, despite those powers never being used as ham handedly as he did. I suspect we’ll see more of these uses soon.

War acts are not under debate here. Those are obvious presidential powers.

No purse strings. No control over banking. No control over prices. No control over exchanges.

Tarrifs are a power of congress delegated to the president.