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Insider Buying Follow-Through

Event-driven rather than calendar-driven. Each week it looks for companies where an insider disclosed an open-market PURCHASE in the previous 45 days, keeps those still liquid and not under surveillance, and holds the 20 with the largest buys.

Why this is expected to work

Insiders trade for many reasons when they sell — diversification, tax, a house, a divorce — but there is essentially one reason to buy your own company on the open market with your own post-tax money. That asymmetry is why the buy signal carries information the sell signal does not. Lakonishok and Lee (2001) found insider-buy portfolios outperformed by roughly 4.8% annually over the following year, and the effect concentrated in smaller companies where analyst coverage is thin. In India the disclosure is mandatory under SEBI's PIT Regulations, filed to the exchange within two trading days, so the data is public, timestamped and free. The 45-day window is a deliberate compromise: shorter and the filing lag eats the signal, longer and it stops being an event and becomes a stale tilt.

insiderevent-drivensignalsebi
Universe
NSE Stocks XNSE
Rebalance
Weekly Equal weighted

How the pipeline works

Filter

Liquid: traded > Rs 2 cr/day

Keeps rows where turnover > 20000000

turnover > 20000000
Filter

Market cap > Rs 500 cr

Keeps rows where market_cap > 5000000000

market_cap > 5000000000
Event

Insider bought in last 45 days

Requires a insider_buy_value event within 45 days

Rank

20 largest insider buys

Selects the top 20 by insider_buy_value

What this template teaches

  • EventTriggerRule — exact-temporality event fields
  • Why event fields cannot be used with a monthly calendar rebalance
  • Conditions applied to the event value itself
  • Weekly cadence matched to disclosure flow
Read the full write-up

Insider Buying Is a Signal. Insider Selling Mostly Is Not.

There are a dozen reasons an insider sells and essentially one reason they buy. That asymmetry is why the buy side of SEBI's mandatory disclosures carries information the sell side does not.