Stock Exchange of Mauritius: How the SEM Works

Last updated: April 2026 | Reading time: ~12 minutes

The Stock Exchange of Mauritius (SEM) is one of Africa's most sophisticated capital markets — a regulated, multi-currency exchange sitting at the crossroads of African ambition and global finance. Whether you're a retail investor curious about Mauritian stocks, an institutional player looking at African exposure, or a company considering a listing, understanding how the SEM works is the essential first step.

This guide breaks down the SEM's structure, markets, indices, trading mechanics, settlement processes, and how investors — local and foreign — can gain access.

## Table of Contents

1. What Is the Stock Exchange of Mauritius?
2. A Brief History of the SEM
3. Markets on the SEM
4. Market Indices: How Performance Is Measured
5. What Can You Trade on the SEM?
6. Trading Mechanics: How the SEM Operates Daily
7. Clearing and Settlement: The CDS
8. Who Regulates the SEM?
9. Listing Requirements at a Glance
10. Can Foreign Investors Trade on the SEM?
11. Taxes and Costs
12. SEM's African Ambitions
13. Tracking Mauritius Markets in Real Time
14. Key Takeaways
15. Sources and Further Reading

## What Is the Stock Exchange of Mauritius?

The Stock Exchange of Mauritius (SEM) — known in French as the Bourse de Maurice — is the primary securities exchange of the Republic of Mauritius, headquartered in Port Louis, the island nation's capital. It is responsible for the operation, promotion, and regulation of a fair and efficient securities market in the country.

Incorporated on March 30, 1989, under the Stock Exchange Act 1988 as a private limited company, the SEM converted to a public company on October 6, 2008, reflecting its expanded mandate and growing regional role. It is a full member of the World Federation of Exchanges (WFE), placing it in the same league as the London Stock Exchange, Nasdaq, and JSE as an exchange that adheres to international standards of market integrity and efficiency.

The SEM is more than a local exchange. With over 200 securities listed across multiple asset classes, issued by a diverse group of local, African, and international entities, it functions as a gateway for Africa-focused and global capital. Its market capitalisation-to-GDP ratio exceeds 90%, the highest in Africa excluding South Africa — a measure of just how deeply integrated the exchange is with the broader Mauritian economy.

> Track live Mauritius market data, listed companies, and price movements on Mansa Markets — a pan-African capital markets terminal covering 13 African exchanges.

## A Brief History of the SEM

Understanding the SEM's present requires knowing where it came from.

• 1989: The SEM opens its doors on July 5, 1989, with the SEMDEX index starting at a base value of 100. Trading at inception used the "Box Method," a rudimentary manual matching system.
• 1991: The Box Method is replaced by the Open Outcry, order-driven, single-price auction system, improving price discovery and transparency.
• 1994: Foreign exchange controls are abolished, and the SEM is formally opened to foreign investors. In its first year of international participation, net foreign inflows reached Rs 38.9 million.
• 1997: SEM launches its first website, becoming one of the first African exchanges to publish 15-minute delayed market data online. Daily electronic trading begins the same year.
• 1998: A Central Depository System (CDS) is implemented, allowing all listed companies to be registered electronically, enabling delivery versus payment (DVP) on a T+3 settlement basis.
• 2002: The SEMTRI (Total Return Index) is launched, capturing both capital gains and dividends — a tool specifically designed for long-term and institutional investors.
• 2008: SEM converts from a private to a public company.
• 2010: SEM begins a fundamental strategic shift toward internationalisation, overhauling its listing framework and regulatory infrastructure to attract global issuers and capital.
• 2014: The SEM-10 index is launched — an investible benchmark comprising the ten largest eligible companies on the Official Market.
• 2015: The SEM Sustainability Index (SEMSI) is introduced, one of the first ESG indices on an African exchange.
• 2018: The Africa Board is launched, spotlighting listed issuers with Africa-centric operations.
• 2024: SEMx is launched — a dedicated growth market for high-growth African companies that may not yet meet main board requirements.
• 2026: SEM announces an extension of trading hours and a planned move to a T+2 settlement cycle, aligning with global standards.

## Markets on the SEM

The SEM operates two primary markets for equity listings, alongside a growing suite of specialised segments.

1. The Official Market

The Official Market is the SEM's main board — home to the most established and well-capitalised companies listed in Mauritius. This is where the flagship indices (SEMDEX, SEMTRI, SEM-10) are calculated and where the most liquid trading activity takes place.

Companies on the Official Market span seven broad categories: banks and insurance, industry, investments, sugar, commerce, leisure and hotels, and transport. There are also dual-listed funds that trade simultaneously on the SEM and exchanges such as the London Stock Exchange (LSE), the Johannesburg Stock Exchange (JSE), the Namibian Stock Exchange, and the Botswana Stock Exchange.

2. The Development & Enterprise Market (DEM)

The DEM is the SEM's second-tier market, designed for smaller and emerging companies that want access to public capital but may not yet meet the full requirements of the Official Market. It operates under a more flexible regulatory framework, making it accessible to growth-stage businesses.

The DEM has its own indices — DEMEX (capital price-weighted) and DEMTRI (total return) — providing investors with tailored benchmarks for this segment.

3. SEMx — The Growth Market (Launched December 2024)

Recognising the funding gap faced by fast-growing African businesses, the SEM launched SEMx in December 2024 as a dedicated segment on the Official Market for high-growth companies that may not meet traditional main board criteria. SEMx allows both private placements and public offerings, giving issuers flexibility in how they raise capital.

The segment incorporates market-making provisions to ensure adequate secondary market liquidity. At launch, SEMx attracted the listing of three companies operating in the food and agro-industry sectors across Africa, each with average annual revenue growth exceeding 25%.

4. The Africa Board

Launched in October 2018, the Africa Board is a dedicated showcase for SEM-listed issuers and products with a predominantly African orientation. To qualify for Africa Board inclusion, a company must demonstrate that at least 50% of its consolidated assets are situated on the African continent, or that at least 50% of its total revenue is generated in Africa (excluding Mauritius).

## Market Indices: How Performance Is Measured

The SEM operates several indices that serve as benchmarks for different investor profiles.

SEMDEX — The Benchmark All-Share Index

The SEMDEX is the SEM's flagship index, launched on July 5, 1989, with a base value of 100. It is a capitalisation-weighted all-share index tracking the price performance of all rupee-denominated ordinary shares listed on the Official Market. Each stock is weighted according to its share of total market capitalisation, meaning large-cap stocks exert more influence on index movements.

Since September 2016, the SEMDEX exclusively tracks Mauritius rupee (MUR)-denominated companies on the Official Market.

SEMTRI — The Total Return Index

The SEMTRI goes beyond price to measure the total return of investing in the Official Market — incorporating both capital appreciation and dividend payments. Launched in October 2002, it is particularly useful for pension funds, insurance companies, and long-term investors who need a complete picture of investment performance, not just price movements.

Gross dividends are assumed to be reinvested into the index, making SEMTRI the most comprehensive measure of actual investor returns over time.

SEM-10 — The Investible Blue-Chip Index

Launched in October 2014, the SEM-10 comprises the ten largest eligible companies on the Official Market by average market capitalisation, liquidity, and investibility. It is designed to meet international standards and serve as an attractive benchmark for both domestic and foreign investors, including institutional players who need a liquid, rules-based index to track.

To be included, a company's shares must be listed on the Official Market, meet minimum liquidity thresholds (trading on at least 50% of sessions during the preceding three months), and have at least 25% of ordinary shares publicly available for investment.

SEM-ASI — The All-Share Index

The SEM-ASI (All Share Index) captures the full breadth of the Official Market, including foreign-currency denominated listings, unlike the rupee-only SEMDEX. It provides a broader view of total Official Market capitalisation.

SEM-AFRIDEX

The SEM-AFRIDEX is a specialised index tracking the performance of Africa-focused securities listed on the SEM, aligning with the exchange's pan-African positioning strategy.

SEMSI — The Sustainability Index

Launched in 2015, the SEM Sustainability Index (SEMSI) tracks the price performance of listed companies that have undergone rigorous ESG assessments based on Global Reporting Initiative (GRI) G4 Guidelines, adapted to the Mauritian context. The four pillars of assessment are: Environmental, Governance, Social, and Economic sustainability.

As of 2025, SEMSI comprises 20 listed companies with a combined market capitalisation exceeding MUR 250 billion — more than double its MUR 93 billion starting size. This growth reflects both the increasing number of companies embracing ESG standards and rising investor appetite for responsible investment products.

DEM Indices: DEMEX and DEMTRI

For the Development & Enterprise Market, the SEM publishes two dedicated indices: DEMEX (a capital-weighted index tracking DEM share prices) and DEMTRI (the DEM's equivalent of the SEMTRI, incorporating total returns including dividends).

## What Can You Trade on the SEM?

The SEM is not just an equities exchange. Its multi-asset product offering includes:

• Equities (Ordinary Shares): The most traded asset class — companies across banking, insurance, sugar, tourism, logistics, and finance.
• Debt Securities and Bonds: Both rupee and foreign-currency denominated bonds tracked by the SEM Bond Index (SEM-BI).
• Exchange-Traded Funds (ETFs): Passive investment vehicles providing broad market exposure.
• Structured Products: Specialised instruments available to qualified investors.
• Eurobonds and Specialist Debt Securities: Targeted at institutional and qualified investors seeking international fixed-income exposure.
• Depositary Receipts (DRs): Allowing foreign companies to list their shares in Mauritius through a local depository arrangement.

This breadth makes the SEM one of the most product-diverse exchanges on the continent.

## Trading Mechanics: How the SEM Operates Daily

Trading System

The SEM operates an order-driven, single-price auction system — an electronic automated trading platform that matches buy and sell orders at prices that reflect true supply and demand. This replaced the original Open Outcry system and has since been upgraded through a series of technology investments.

Trading Currency

Trading on the SEM is conducted primarily in Mauritian Rupees (MUR). However, the SEM's multi-currency platform supports trading, clearing, and settlement in USD, EUR, GBP, ZAR, and MUR, making it uniquely accessible to international issuers and foreign investors who prefer transacting in major currencies.

It is the only exchange in Africa that can list, trade, and settle products across five currencies.

Trading Hours and Days

Trading takes place five days a week (Monday through Friday), for approximately five and a half hours per session. The exchange operates in Mauritius Standard Time (MST, GMT+4), and does not observe Daylight Saving Time.

In April 2026, the SEM extended its trading hours as part of a broader effort to enhance market infrastructure and support internationalisation — making it more accessible to investors in different time zones.

Price Limits

Each share (excluding foreign-currency denominated shares) is subject to a maximum price movement of ±20% per trading session, a circuit breaker mechanism that prevents extreme intraday volatility.

Transaction Fees

A maximum trading fee of 1.25% applies to transactions on the market.

## Clearing and Settlement: The CDS

The Central Depository System (CDS), established in 1998 through the Bank of Mauritius, is the backbone of post-trade infrastructure at the SEM. All listed securities are registered in the CDS, which provides:

• Electronic book-entry settlement — eliminating the need for physical share certificates.
• Delivery versus Payment (DVP) — ensuring that the transfer of securities occurs simultaneously with the corresponding payment, eliminating counterparty risk.
• T+3 Settlement Cycle — trades are currently settled three business days after the transaction date. The SEM has announced plans to transition to a T+2 settlement cycle within the next year, aligning with global market standards.
• Clearing Guarantee Fund — a fund established through the Bank of Mauritius that provides assurance of securities and fund settlement, protecting against participant default.

## Who Regulates the SEM?

The SEM operates within a multi-layered regulatory framework:

• The Stock Exchange Act 1988: The foundational legislation that established the SEM and the original Stock Exchange Commission (SEC).
• The Financial Services Commission (FSC): The primary regulatory authority for the securities market in Mauritius today. The FSC supervises all exchange activities, enforces compliance, and protects investors.
• The SEM's Own Listing Rules and Trading Rules: Stringent internal regulations governing listing eligibility, continuous disclosure, corporate governance, and market conduct.
• The World Federation of Exchanges (WFE): As a full WFE member, the SEM is bound by international best practice standards for exchange governance and market integrity.

The SEM also has an Investor Protection and Complaint mechanism, giving market participants formal recourse in cases of disputes or misconduct.

## Listing Requirements at a Glance

Official Market

To list on the Official Market, a company must generally:

• Have a minimum expected market capitalisation of MUR 20 million.
• Demonstrate a minimum three-year audited trading record prior to application (exceptions apply).
• Issue at least 25% of shares to the public, with a minimum of 200 shareholders (a phased approach is allowed: 15% in Year 1, 20% by Year 3, 25% by Year 5).
• Submit comprehensive listing particulars — a document that gives investors the information needed to make an informed decision.

International issuers seeking a secondary listing on the SEM can leverage a fast-track listing route (introduced in 2017), which allows them to submit the same application documents approved by their primary exchange — significantly reducing administrative burden.

Development & Enterprise Market (DEM)

The DEM applies a more flexible entry framework:

• No mandatory minimum market capitalisation threshold at entry.
• Companies without a three-year track record may be admitted if they submit a credible three-year business plan certified by an independent financial adviser.
• A minimum of 10% of shareholding in public hands, with at least 100 shareholders (with an undertaking to reach these thresholds within the first year if not met at listing).
• For mineral and exploration companies, compliance with internationally recognised reporting standards (JORC Code, NI 43-101, or SAMREC Code) is mandatory.

Africa Board Inclusion

To be featured on the Africa Board, a company must prove that at least 50% of its consolidated assets or total revenue are Africa-based (excluding Mauritius).

## Can Foreign Investors Trade on the SEM?

Yes — and notably without significant barriers.

The SEM was opened to foreign investors in 1994 following the abolition of exchange controls. Key provisions for international participants include:

• No approval required to trade shares (unless the investment is for the purpose of legal or management control of a Mauritian company).
• No individual shareholding restriction in most companies (the exception: foreign investors cannot hold more than 15% individually in a sugar company).
• No capital gains tax on listed securities.
• No withholding tax on dividends from officially listed companies (a Solidarity Levy applies for certain Mauritian residents in specific circumstances).
• Full currency convertibility — settlements can be made in a foreign currency, and foreign currency accounts can be opened in Mauritius.
• No capital repatriation controls — profits and investment proceeds can be freely repatriated.

This combination of an open capital account, no capital gains tax, and a multi-currency trading platform makes the SEM one of the most investor-friendly exchanges on the African continent for international participants.

## Taxes and Costs

Note: Tax treatment may vary for individual investors depending on their country of residence. Consult a qualified tax adviser.

## SEM's African Ambitions

The SEM is not content with being Mauritius's local bourse — its strategic orientation is explicitly pan-African and international. Several initiatives reflect this:

Multi-Currency Platform

The SEM's trading, clearing, and settlement infrastructure supports five currencies (MUR, USD, EUR, GBP, ZAR) — the only exchange in Africa with this capability. This removes a significant barrier for African companies that prefer to raise capital in hard currencies.

55+ International Listings

From only a handful of foreign listings before 2010, the SEM now hosts over 55 international issuers across equity, debt, ETFs, and structured products. These come from diverse jurisdictions and include nine dual-listed issuers also listed on exchanges such as the JSE, the Namibian Stock Exchange, and the Botswana Stock Exchange.

SEMx: Africa's Growth Capital Platform

Launched in December 2024, SEMx addresses the funding gap that fast-growing African companies face. By lowering listing barriers while maintaining market integrity provisions (including mandatory market-making for secondary liquidity), it offers a viable path for high-growth African businesses to access public capital markets.

Financial Literacy: SEMYIA Trading Game

Since 1993, the SEM has run the SEMYIA Trading Game — a multi-round stock market simulation competition for Grade 12 students. Over 21,000 students have participated since inception. The 2025 edition attracted 600 students from 73 colleges, who each managed a hypothetical Rs 200,000 portfolio over two months, graded 60% on portfolio performance and 40% on the quality of their investment analysis reports.

## Tracking Mauritius Markets in Real Time

Monitoring the SEM's markets, listed companies, and price movements requires access to reliable, structured data.

Mansa Markets is a pan-African capital markets terminal built for investors, analysts, and professionals who need consistent, organised data across 13 African exchanges — including the SEM. From equity prices and index performance to company profiles and market snapshots, Mansa Markets brings African market data into a single, accessible platform.

If you're looking to expand beyond Mauritius and build a pan-African investment portfolio, the Mansa Markets Beginner's Guide to Investing in African Stock Markets is an excellent starting point — covering the mechanics, risks, and opportunities across the continent's diverse exchanges.

## Key Takeaways

• The Stock Exchange of Mauritius (SEM) was established in 1989 and is one of Africa's leading exchanges, with a market cap-to-GDP ratio exceeding 90% — the highest on the continent outside South Africa.
• The SEM operates two main markets — the Official Market and the Development & Enterprise Market (DEM) — plus the newer SEMx growth segment.
• Key indices include SEMDEX (all-share benchmark), SEMTRI (total return), SEM-10 (blue-chip investible index), and SEMSI (ESG/sustainability index).
• Trading uses an automated, order-driven, single-price auction system, conducted in multiple currencies — MUR, USD, EUR, GBP, and ZAR.
• Settlement is handled through the CDS on a T+3 basis (moving to T+2 within the year).
• Foreign investors can trade freely — no capital gains tax, no withholding tax on dividends, and no capital repatriation restrictions.
• The SEM's Africa Board and SEMx platform reflect its ambitions as a regional capital markets hub.

## Sources and Further Reading

1. Stock Exchange of Mauritius — SEM at a Glance. stockexchangeofmauritius.com
2. Stock Exchange of Mauritius — Investor Education FAQs. stockexchangeofmauritius.com
3. Stock Exchange of Mauritius — SEMDEX Index Methodology. stockexchangeofmauritius.com
4. Stock Exchange of Mauritius — SEMTRI Index Methodology. stockexchangeofmauritius.com
5. Stock Exchange of Mauritius — SEM-10 Index Methodology. stockexchangeofmauritius.com
6. Stock Exchange of Mauritius — Official Market Admission Requirements. stockexchangeofmauritius.com
7. Stock Exchange of Mauritius — DEM Admission Requirements. stockexchangeofmauritius.com
8. Wikipedia — Stock Exchange of Mauritius. en.wikipedia.org
9. Mauritius Trade — Stock Exchange. mauritiustrade.com
10. Devex — Stock Exchange of Mauritius Ltd. devex.com
11. African-Markets.com — SEM Overview. african-markets.com
12. SSE Initiative — Stock Exchange of Mauritius Profile. sseinitiative.org
13. TradingHours.com — Stock Exchange of Mauritius. tradinghours.com

This article is intended for informational and educational purposes only and does not constitute investment advice. Always conduct your own research and consult a licensed financial adviser before making investment decisions.