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Research Note · No. 041
Behavioural Finance · Sideways Markets

The Rule,
Not the Range.

Why the Sensex at 70,000–86,000 is a laboratory for a single uncomfortable truth: in a sideways market, investors without a rule experience motion without progress.
By Dharmendra Satapathy  ·  NextLevel Education Private Limited  ·  Mumbai

When a market oscillates within a range for months, the investor's experience is determined by a single variable — whether a rule exists that forces action at the extremes. Not intelligence. Not conviction. Not professional status. A rule.

The Nifty 50 between October 2021 and March 2023 is one of the cleanest sideways markets in recent memory. It started at 17,671. It ended at 17,360. Seventeen months of heartbeat — up to 18,758, down to 15,780, back to almost exactly where it began. Endpoint return: minus 1.76%.

That is the defining feature of a sideways market. The investor who did nothing earned less than nothing. But that same 17-month window was a gift to anyone with a mechanism — a rule, a mandate, a structure — that required action when the market swung.

Exhibit 01
The 17-Month Oscillation
Nifty 50 · Oct 2021 – Mar 2023 · Monthly close
19,000 18,000 17,000 16,000 15,500 DEPLOY TRIM TRIM DEPLOY START 17,671 END 17,360 (−1.76%) LOW 15,780 HIGH 18,758 Oct 21 Apr 22 Oct 22 Mar 23

Now consider three investors, each starting with ₹10 lakh on 1 October 2021. Same market. Same seventeen months. Same endpoint. Three different rules — or the absence of one.

A
Lumpsum Nifty · No Rule
Bought on Day 1. Held to Day 510.
−1.76%
₹9,82,401
B
Rule-Based Nifty · 70/30 with ±5% Triggers
4 trades. Trim at tops. Deploy at dips.
+2.88%
₹10,28,758
C
60/40 Hybrid · Quarterly Rebalance
No skill required. Structure does the work.
+2.94%
₹10,29,386

Investor A did nothing wrong. That was the problem. In a sideways market, doing nothing is doing something — and what it does is absorb every swing without monetising one.

The spread between Investor A and Investor C is 470 basis points, earned on a market that technically went nowhere. That gap did not come from stock selection. It did not come from timing. It came from a mechanism that required equity to be trimmed when it rallied and added when it fell, regardless of how anyone felt.

Investor B did the same thing manually with four trades. Investor C let the fund structure do it quarterly. Both converted volatility into return. Investor A, holding the exact same underlying index, converted volatility into heartbeat.

What this backtest does not prove

The edge is modest. And that is the point.

470 basis points over 17 months is not a dramatic outperformance. It is an honest one. In shallow sideways markets, rules do not deliver multiples — they deliver steadier paths, fewer behavioural errors, and the difference between a negative ending and a positive one. The real compounding is not in the numbers. It is in the client who stays invested because the path was livable, and the twenty years of returns that follow.

The takeaway, stated plainly.

In a range-bound market — whether Nifty at 17,000–18,500 then, or Sensex at 70,000–86,000 now — returns do not accrue to the smartest investor. They accrue to whichever investor has a binding rule that forces action at the extremes. Hybrid funds have this rule by mandate. Disciplined equity managers have it by process. Direct equity investors technically have cash to deploy and profits to trim — and almost never do either, because their rule is their gut, and their gut rocks with the market.

The range is not the enemy. The absence of a rule is.