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Behavioural Finance · Compounding

The Behavior
Tax Calculator

Miss 10 best days out of 6,250. Lose half your wealth. Calculate the exact rupee cost of stepping out of the market at the wrong moment.

Scenario Inputs

Drag sliders · Watch the Behavior Tax compound

₹10 Lakhs
25 years
13.5 % p.a.
10 days
The Uncomfortable Truth

Volatility is two-sided. The best days and the worst days are not enemies. They are neighbours. Nifty’s single largest rally in history arrived two trading days after its single largest loss. Since 2000, 16 of the 20 best days have fallen within 10 days of one of the 20 worst. If you step out during the pain to “avoid the crash,” the mathematics does the rest: you have not escaped the loss. You have guaranteed the missed recovery.

Fully Invested
₹23.4L
13.5% CAGR
Behavior Tax
−₹14.8L
63% of wealth lost
After Missed Days
₹8.6L
9.0% effective CAGR
Final Corpus by Scenario
₹10L → 25 years → Varying days missed
The Per-Day Cost
Average Cost Per Missed Day
−₹1.48L
% of Trading Days
0.16%
Key Insight

Missing just 10 days out of 6,250 trading days costs you ₹14.8 lakhs on a ₹10L starting corpus over 25 years. These are not random days. Best days cluster immediately after worst days — so panic-selling during a crash mathematically guarantees you miss the recovery.

Research Paper
The Behavior Tax · Full Analysis
Read →
Note: CAGR impact of missing N best days is modelled on historical Nifty 50 daily return data (Jan 2000 – Mar 2025). Each "best day" missed reduces compounded CAGR non-linearly — the first 5 days missed have outsized impact (biggest rallies), and then the effect tapers. Illustrative only. Past performance is not indicative of future returns. Mutual fund investments are subject to market risks. Read all scheme related documents carefully before investing.