Negative and Exclusionary Screening

Introduction to Negative and Exclusionary Screening

Negative screening is about knowing where not to invest.

Before analyzing balance sheets or forecasting returns, many investors first remove companies involved in harmful sectors or serious misconduct.

These exclusions are based on clear rules like banning coal producers, limiting exposure to controversial weapons, or dropping firms involved in major scandals.

This lesson breaks down the five core tools investors use to build portfolios that reflect their values from the start.

Sector & Product Bans

Sector and product bans are the most direct filter.

Investors define activities, such as thermal‑coal mining, oil‑sands refining, tobacco production, civilian firearms, cluster munitions, gambling, and adult entertainment, that are never tolerated.

Every security issued by a firm engaged in the banned line is excluded regardless of revenue share, momentum, or governance pedigree.

The clarity simplifies compliance, audits, and client communication while sidelining high legal and stranded‑asset risk.

Alex’s Sector Exclusion List 

Alex applies a sector ban. He exports a global fund’s holdings into Excel and tags each issuer with industry codes from his data vendor.

Any pure‑play coal miner, tobacco maker, or handgun seller is deleted.

Forty‑two names, or 5 % of the total weight of his portfolio, vanish, trimming exposure to Australian resources and US staples.

Alex names the sheet “Red List” and scripts a cross‑check that blocks future trades in those tickers, locking the policy into daily workflow.

Norm‑Based Screens 

Norm‑based screens judge conduct, not products.

Data providers scan lawsuits, NGO findings, sanctions, and media for breaches of the UN Global Compact, OECD Guidelines, ILO labour rights, or Paris climate targets.

A confirmed breach moves the company onto an exclusion roster until credible remediation is independently verified.

The rule protects portfolios from reputational shocks and aligns capital with globally accepted baseline standards of human and environmental behavior.

Revenue Limits 

Revenue thresholds add nuance where blanket bans feel too blunt. Investors may tolerate limited exposure, often less than 5% of sales, while excluding companies that are meaningfully dependent on the flagged activity.

An example of revenue thresholds investors often use:

5 % for thermal coal
10 % for military weapons
15 % for animal testing.

Analysts use company filings to estimate segment-level revenue. If a company exceeds the threshold, it remains ineligible until its exposure falls below the limit for two consecutive reporting periods.

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