Open market operations and liquidity

Chapter 6 showed the corridor sets boundaries. Where inside those boundaries the overnight rate sits is decided by how much surplus cash the banking system is holding, and managing that is a continuous operational job rather than a six-weekly vote.

Surplus and deficit

Surplus — banks collectively have more cash than they need. They compete to place it, so the overnight rate drifts down towards the SDF floor.

Deficit — banks collectively are short. They compete to borrow, so the rate drifts up towards the MSF ceiling.

Neither is caused by the MPC. Liquidity moves for reasons largely outside monetary policy:

• Government spending and tax collection. When taxes are paid, cash leaves banks for the government's account at the RBI. When the government spends, it returns. These swings are large and calendar-driven.
• Currency in circulation. Cash withdrawn for a festival season leaves the banking system.
• Foreign exchange flows. RBI purchases of foreign currency inject rupees; sales withdraw them.

So liquidity management is substantially about offsetting flows the central bank did not choose, to keep the operative rate near the policy rate.

The instruments

The liquidity adjustment facility (LAF). Day-to-day repo and reverse repo operations: the RBI lends against collateral to inject cash, or absorbs cash, for short periods. This is the routine tool, reversible by design.

Open market operations (OMOs). Outright purchases or sales of government securities. Buying injects cash permanently; selling withdraws it permanently.

The distinction is the point. LAF handles temporary mismatches; OMOs change the durable level of liquidity. Using an OMO for a week-long tax-season deficit would be using a structural tool for a cyclical problem.

Variable rate operations of longer tenor sit between the two, and the choice of tenor is itself a signal about how long the RBI expects conditions to persist.

Working the problem

Repo unchanged, large OMO purchases.

System liquidity rises. The RBI pays cash for securities; banks hold more cash and less paper.

The overnight rate drifts towards the SDF floor. A cash-rich system has nowhere better than the floor, so the effective rate falls even though the announced rate did not move — chapter 6's point about the announced rate not always being the operative one.

Bond prices rise and yields fall. A large buyer is entering the market. From chapter 3 of the Fixed income subject, price and yield move opposite, so this lowers yields across the curve — which is a loosening of financial conditions achieved without touching the repo rate.

That is the whole lesson: liquidity operations are monetary policy, even when the policy rate is unchanged. A reader watching only MPC announcements is watching one of two levers.

Why the stance is announced separately

The MPC announces both a rate decision and a stance — accommodative, neutral, or withdrawal of accommodation. The stance is forward guidance about liquidity and about the likely direction of future rates.

It matters because expectations move market rates before the RBI does. If the market believes cuts are coming, longer-term rates fall now. A central bank that is understood needs to move its own rate less to achieve the same effect, which is why the minutes and the stance are instruments rather than commentary.

The risk is the mirror image: guidance that is reversed damages the credibility that made it work.

What to watch

• Where the overnight rate sits relative to repo, SDF and MSF. The clearest single read on conditions.
• The net LAF position — whether the system is in surplus or deficit, and by how much.
• OMO announcements, which signal a durable change rather than a temporary one.
• The stance, and whether it matches what the rate decision did.

A rate cut alongside liquidity withdrawal is a mixed message, and the market will price the combination rather than the headline.

The point

The corridor sets the boundaries; system liquidity decides where inside them the overnight rate sits. Liquidity moves largely for reasons the central bank did not choose — tax flows, currency demand, foreign exchange — so the liquidity adjustment facility offsets temporary swings while open market operations change the durable level. Buying securities injects cash, pushes the effective rate towards the floor and lowers bond yields, all without the policy rate moving.