Every trader who has blown up an account can tell you the exact moment it happened. It was never the first loss. It was the third, or the fifth — the one taken to make back the earlier ones.
A daily loss limit is a number you decide before the market opens, after which you stop for the day. No exceptions, no "just one more". This article explains how that number works in SENSEX weekly options, and why writing it into a rule beats promising yourself you will be disciplined.
SENSEX weekly options trade on BSE. One lot is 20 quantity, strikes are spaced 100 points apart, and the weekly contract expires on Thursday.
Suppose SENSEX is at 74,500 and the 74,500 call is quoted at ₹400. One lot costs 20 × ₹400 = ₹8,000. If that option falls to ₹350, you are down 50 points, which is 20 × 50 = ₹1,000 on one lot.
The arithmetic is simple and unforgiving. Every one-point move in the option price is ₹20 per lot in your account. Trade four lots and it is ₹80 per point. Trade ten lots and a 40-point wobble — perfectly normal inside five minutes on expiry week — is ₹8,000.
Willpower works fine at 09:15 when you are calm and nothing has happened yet. It works badly at 13:30 when you are down ₹40,000 and the market is finally moving your way.
This is not a character flaw. It is how the brain handles loss. Once you are behind, a normal-sized trade feels pointless and a double-sized trade feels reasonable, because only the big one gets you back to flat today. The desire to end the day even is stronger than the desire to end the year profitable.
Think of an auto-rickshaw driver who has decided he will drive until he earns ₹1,500. On a bad day he is still out at 11 PM, tired, taking risks on empty roads for the last ₹200. On a good day he goes home at 4 PM. His rule has him working hardest exactly when he is least fit to work. A time limit would have protected him; an earnings target did not.
A daily loss limit is the time limit. It is a rule that does not care how you feel when it triggers.
Notice what the picture does not claim. The circuit breaker did not turn a losing day into a winning day. It turned a bad day into a survivable one. That is the whole job.
The limit is usually expressed as a percentage of trading capital, and it has to survive the ugly arithmetic of drawdowns. Losing 20% means needing 25% to get back to flat. Losing 50% means needing 100%.
A commonly used structure looks like this:
The relationship matters more than the exact numbers. If your daily limit is ten times your per-trade stop, you can lose ten trades before it ever triggers — by then the damage is done and the rule was decorative.
A rule you enforce yourself is a suggestion. The ones that hold are the ones with a mechanism:
A daily loss limit does not make a losing strategy profitable. If your entries have no edge, the circuit breaker only slows the rate at which capital disappears.
What it does is keep the account alive long enough for you to find out whether there is an edge at all. Most traders never get that far, because a single uncapped day ends the experiment before the data arrives.
This is educational content about how loss limits work. It is not advice to trade, and nothing here predicts what any market will do.