How to stress-test an SIP for a market fall year

The default projection is a straight line

SIP calculators usually compound a constant expected return. Real years wobble: a −20% equity year, a flat year, then a recovery. Your instalments in the fall buy cheaper units; your stomach may still want to stop. A stress test asks whether the goal survives a ugly middle, not whether the base case looks pretty.

Three simple re-runs

First, drop expected return by a few points (for example 12% to 8%) for the full tenure and note the corpus. Second, keep the base return but shorten the tenure by a year to mimic a late start or a pause. Third, if you use step-up, set step-up to 0% for a raise-less decade. The SIP and step-up calculators are enough for this desk exercise.

If the goal fails in two of three stress runs, raise the instalment, extend the date, or cut the target—before the fall happens.

Process beats prediction

Decide in advance: continue SIPs through a defined fall, keep an emergency fund outside equity, and avoid leverage. The calculator will not tell you the next crash date. It will tell you whether your plan was only surviving on optimistic arithmetic.