Imagine you are reviewing a portfolio for a client who is concerned about their high exposure to a single sector, such as Information Technology. You observe that while the portfolio’s overall volatility is high, a significant portion of that risk stems from the concentration of the stock holdings themselves rather than the movement of the Nifty 50 index.
As an analyst, your job is to differentiate between the risk that can be mitigated through diversification and the market-driven risk that remains regardless of how many stocks you hold. This distinction is the bedrock of modern portfolio theory and critical for your NISM exam preparation.
Non-diversifiable risk, often termed systematic or market risk, represents the uncertainty inherent in the entire financial system. Factors such as changes in Reserve Bank of India (RBI) interest rate policies, geopolitical instability, or systemic inflation shocks impact every asset class to some degree. Because these forces are macroeconomic and market-wide, no amount of portfolio diversification can eliminate them. Beta is the quantitative expression of this sensitivity, measuring how much an individual asset moves in tandem with the broader market.
When you build a model using the Capital Asset Pricing Model (CAPM), you are specifically pricing this non-diversifiable risk because the market does not reward investors for bearing risk that could have been easily avoided.
Conversely, diversifiable risk—or unsystematic risk—is unique to a specific company or industry. Examples include a labor strike at a particular manufacturing plant, a failed product launch, or a management scandal. These events are independent of the broader market environment and can be neutralized by holding a sufficiently large and varied basket of assets. In a well-diversified portfolio, the negative impact of an idiosyncratic failure in one company is offset by the positive performance or stability of others.
A professional analyst focuses on identifying these idiosyncratic risks during fundamental analysis, as they represent the ‘stock-specific’ factors that can be managed through strategic asset allocation.
To visualize this, consider an investor holding shares in only one pharmaceutical company. If the company faces a sudden regulatory hurdle from the CDSCO regarding its flagship drug, the stock price may collapse entirely. However, if the investor holds a diversified basket of twenty stocks across sectors like FMCG, Banking, and Energy, the impact of that specific pharmaceutical crisis is diluted significantly. The systematic risk remains, but the unsystematic component has been effectively hedged away.
Mastering this distinction allows you to justify why you might recommend a high-beta stock; if the stock’s fundamentals are strong, the extra return expected from the market compensates for the systematic risk, while the unsystematic risk can be minimized through your portfolio design.
Nuance
Check Your Understanding
An analyst is comparing two portfolios: Portfolio A holds 50 stocks across 10 different sectors, while Portfolio B holds 3 stocks in the same industry. Which of the following is true regarding their risk profile?
Which of the following events would be classified as an example of unsystematic risk for a logistics company listed on the NSE?
This is a companion read for Section 12.5 — Concepts of Market Risk (Beta) from PASS Research Analyst Certification Examination by Akhilesh Gururani, available on Amazon Kindle.
Copyright © 2026 Akhilesh Gururani. All rights reserved.