The Fed's move this time is no small matter—quantitative tightening has officially been paused, and the next step may be a reversal.

Wall Street is now watching a new term: RMP, which stands for "Reserve Management Purchases." It sounds official, but to put it simply, it means the Fed is preparing to inject liquidity back into the market. Although officials have repeatedly distanced RMP from previous quantitative easing (QE), saying they are completely different, investors know better—as long as it increases liquidity, the label doesn't really matter.

Why do this all of a sudden? The repo market has been turbulent lately. This $12 trillion market has seen unsettling interest rate swings. The Fed clearly couldn't sit still. Some analysts speculate that as soon as next week's FOMC meeting, the Fed might officially announce the launch of RMP.

How will it work in practice? One investment bank team predicts: starting January next year, the Fed may buy $35 billion in short-term Treasuries each month. Considering about $15 billion in mortgage-backed securities mature monthly, the Fed's balance sheet could see a net increase of around $20 billion per month.

What does this mean for the market? Increased liquidity is a sure thing. The signal of a monetary policy shift is now very clear. The key question is whether the Fed can really stabilize the turmoil in the repo market. After all, this isn't just a simple policy tweak—it could mean a complete redefinition of the monetary policy framework.

The era of quantitative tightening is ending. Is a new balance sheet expansion cycle really here? The market is waiting for the answer.