The Swiss Market Index tracks 20 large, liquid Swiss equities using capped free-float market-capitalization weights.
The Swiss Market Index (SMI) is Switzerland’s principal blue-chip equity benchmark. It contains 20 of the largest and most liquid equities in the Swiss Performance Index universe and weights them by capped free-float market capitalization.
The SMI draws its constituents from the broader SPI universe. SIX ranks eligible securities using free-float-adjusted market capitalization and cumulative order-book turnover. Buffer rules reduce unnecessary turnover around the final selection ranks.
The ordinary annual review becomes effective in September. A company can also leave or enter because of mergers, delistings, major corporate actions, or extraordinary index rules. The current list should therefore be checked on a dated SIX factsheet rather than copied from an undated article.
The SMI is often described as a Swiss economic indicator, but its direct meaning is narrower: it measures the market performance of a selected set of large, liquid listed equities.
A simplified capped free-float weight is:
Where:
SIX applies an 18% cap during quarterly adjustments. Between ordinary adjustments, ad hoc recapping can occur when two constituents each exceed 20%. The cap limits single-name dominance but does not create equal weights or guarantee balanced sector exposure.
Suppose a constituent has an uncapped weight of 24% before a scheduled capping adjustment. In a simplified illustration, its index weight is reset to 18%, and the excess is redistributed across other constituents according to the methodology.
If that constituent then rises 4% while its starting index weight is 18%, its approximate contribution is:
18% x 4% = 0.72 percentage points
If the other 82% of the index is unchanged, the SMI rises by roughly 0.72%. Actual index calculations account for all constituents, corporate actions, divisor adjustments, and the selected return series.
SIX calculates both price and return variants. The distinction matters:
| Series | Dividend treatment | Typical interpretation |
|---|---|---|
| SMI price index | Excludes ordinary cash dividends | Share-price movement of the basket |
| SMI gross-return index | Reinvests gross distributions | Return before investor-specific taxes and costs |
| Other product or benchmark series | Depends on its rules | Must be checked in the product documents |
A fund’s return may differ from either index because of fees, withholding taxes, cash, replication choices, transaction costs, and timing. A CHF index return also may differ from the return translated into another investor’s home currency.
| Index | Coverage | Main distinction |
|---|---|---|
| SMI | 20 large, liquid securities | Swiss blue-chip benchmark with an 18% constituent cap |
| SPI | Broad Swiss equity universe | Includes substantially more companies and size segments |
| SLI | A broader blue-chip basket than SMI | Uses its own stronger capping structure |
| SMIM | Companies below the SMI segment under index rules | Swiss mid-cap benchmark |
The correct benchmark depends on the portfolio’s eligible universe. A broad Swiss equity fund can differ substantially from the 20-security SMI even when both are labelled “Swiss equities.”
The SMI serves as a benchmark for Swiss blue-chip portfolios and as an underlying for index funds, ETFs, futures, options, structured products, and mandates. Analysts use it to study large-company equity performance, risk, and sentiment in the Swiss market.
Many SMI companies conduct business globally. Their share prices can respond to foreign demand, exchange rates, regulation, commodity costs, and international financing conditions. The SMI can therefore move differently from Swiss domestic output, employment, or household income.
Treating the SMI as the whole Swiss market. It is a concentrated blue-chip subset of the broader SPI universe.
Assuming 20 holdings guarantee diversification. A few large issuers and sectors can still drive a substantial share of return and risk.
Ignoring the return series. Price and gross-return indexes differ because of dividends.
Equating Swiss listing with Swiss-only exposure. Constituent revenues, costs, operations, and currencies can be global.
Assuming a fund exactly earns the index return. Real products incur costs and may use replication methods that create tracking differences.
The SMI is exposed to equity losses, issuer and sector concentration, currency movements, global demand, regulation, and valuation changes. Capping reduces extreme constituent weights but cannot eliminate concentration or market risk. Derivatives and structured products linked to the SMI can introduce leverage, counterparty, liquidity, and path-dependent risks beyond the index itself.
Past index performance does not guarantee future results. This article provides general financial education, not investment advice or a recommendation of a Swiss security or product.