Promoters cannot quietly buy or sell their own company's stock. Under SEBI's Prohibition of Insider Trading Regulations, any promoter, designated person, or their immediate relative who trades more than Rs 10 lakh worth of shares in a calendar quarter must be disclosed to the stock exchanges within two trading days, whether the trade is a purchase or a sale. That rule turns what would otherwise be private information into a public filing almost anyone can read.
September 2026 produced two clean, ordinary examples of the mechanism working. Nureca Limited filed a manual insider trading disclosure on 28 September 2026 after promoter Saurabh Goyal bought shares through a route that fell outside the exchange's automatic system-driven disclosure, and LCC Projects Limited filed an updated PIT code with both exchanges on 17 September, formally setting its trading window closure from quarter-end until 48 hours after results. Neither event made headlines, which is exactly the point: this machinery runs quietly, every week, on companies nobody is watching.
The two rules that govern this
There are actually two separate disclosure regimes, and they get confused often. The Prohibition of Insider Trading Regulations govern promoters and designated persons specifically, because of their access to unpublished price-sensitive information, with a Rs 10 lakh per-quarter threshold and a two-day disclosure window. A different rule, the Substantial Acquisition of Shares and Takeovers Regulations, applies to any acquirer at all, including mutual funds with no insider status, once their stake crosses 5% or moves 2%, the mechanism our what mutual fund managers are buying piece covers.
Why the trading window matters as much as the threshold
The window closure is arguably the more important rule, because it stops insiders trading at all during the exact period they are most likely to know something the market does not. From the end of a financial quarter until 48 hours after results are declared, promoters and designated persons cannot trade, full stop, regardless of size. LCC Projects' updated PIT code filed on 17 September 2026 is a routine example of a company formalising exactly this calendar.
A real trade outside that window still needs reading carefully. In June 2026, three promoter group entities of MSP Steel and Power Limited acquired more than 52 lakh shares worth Rs 21.55 crore in the open market, a disclosure that became public within the standard two-day window and is the kind of filing worth understanding rather than reacting to on headline alone.
How to read a promoter filing without overreacting
Size relative to existing holding matters more than the headline rupee figure. A promoter adding 1% to an already-large stake signals differently than one making a first-ever purchase, and a filing in isolation tells you neither. Look for a pattern across quarters, which our promoter holding piece explains how to track using quarterly shareholding data.
Context also decides whether a sale is bearish. A promoter sale can fund an unrelated need, release a pledge, or rebalance a concentrated personal portfolio, none of which reflect a view on the company, which is why our promoter pledging piece treats pledge-driven sales as a distinct, more serious category. Promoter and institutional signals are only one layer of the picture, alongside the aggregate flows our FII vs DII and how to read FII and DII activity pieces track, and a sudden move on a filing like this is exactly when the circuit breaker rules can kick in.
Risks to monitor
The rule exists because promoters know things ordinary shareholders do not, and forcing disclosure closes that information gap within two days rather than leaving it hidden until the next results call. Reading the filings well, rather than reacting to the headline, is what actually turns this public data into an edge.