3 MIN · A 3-minute read · Updated 30 October 2026
THE 10-SECOND VERSION
The SMI holds Switzerland's 20 biggest, most liquid stocks, but Roche, Novartis and Nestlé make up almost half of it.
WHAT'S HAPPENING
The Swiss Market Index (SMI) is calculated by SIX. It contains the 20 largest and most liquid stocks on the Swiss exchange and covers more than 75% of the free-float value of the whole Swiss market. Each company's weight depends on its free-float market value.
Because three companies are so large, SIX caps any single member at 18% at each review, and re-caps between reviews if two members exceed 20% (methodology). The composition is reviewed once a year, in September.
How concentrated is it? Official weights are licensed by SIX, but the holdings of an SMI tracker give a close picture. According to whichindex.com, based on an Xtrackers SMI ETF on 29 October 2026:
Roche 18.59%, Novartis 15.33%, Nestlé 13.89%: together 47.8%.
Next come UBS (7.74%), ABB (7.53%), Zurich (6.03%) and Richemont (5.72%).
The top 10 make up 83.11% of the index.
ETF weights can differ slightly from the official index, for example where Roche sits above the 18% cap between reviews.
What that means: the SMI is heavy in health care and consumer staples, sectors that tend to move less in downturns but lag in tech-driven rallies. A day when pharma falls can pull down the whole index even if most members rise.
The SMI is a price index: dividends are not included. SIX also calculates versions with dividends reinvested, which show a fuller picture of long-run returns.
The big three are also very different businesses: two global drugmakers and the world's largest food company. Much of their revenue is earned outside Switzerland, in other currencies.
THE NUMBER
47.8%
Weight of Roche, Novartis and Nestlé in an SMI tracker, 29 Oct 2026. Almost one franc in two invested in an SMI tracker goes into three companies. Add UBS and ABB and you pass 60%. That is concentration you would not accept in a self-built portfolio, which is why it is worth knowing before calling the SMI 'the market'.
WHAT IT MEANS FOR YOUR FRANCS
"Swiss market" is not broad: an SMI fund is largely a bet on three companies. Broader indices like the SPI include far more firms.
Home bias: many Swiss investors hold mostly Swiss shares. The SMI's sector mix leaves out much of global tech.
Currency: SMI companies earn largely abroad, so a strong franc can weigh on their reported profits.
3 TERMS IN 30 SECONDS
Free float: Shares that can actually be traded, excluding large fixed stakes. The SMI weights by free-float value.
Capping: A rule limiting any member's weight, here to 18%, so one stock cannot dominate the index.
Price vs total return: A price index ignores dividends. A total-return version assumes they are reinvested.
WHAT TO WATCH NEXT
The next annual index review in September 2027.
Pharma news: Roche and Novartis together are about a third of the index.
The Swiss capital rules for UBS, the largest bank in the index.
THE 3-MINUTE TAKEAWAY
The SMI is the headline number for Swiss shares, but it behaves like a pharma-and-food index with a bank and an engineering group attached. That is not good or bad in itself; it is simply something to know. If you want to understand why the SMI moved today, check Roche, Novartis and Nestlé first.
GO DEEPER
More explainers like this: The 3-Minute Franc. Everything you need to know about your francs, 3 minutes each.
General information only, not investment, tax or legal advice, and not a recommendation to buy or sell any financial instrument. Figures come from the sources linked above and are preliminary. Independent; not affiliated with any exchange or authority.
Allgemeine Information, keine Anlageberatung. · Information générale, pas un conseil en placement. · Informazione generale, non consulenza in investimenti.