In the past, the S Group's hypermarkets differed a lot from each other, as the cooperatives were allowed to choose their own concept. The names Sokos-market and Prisma, among others, were used. The S Group's first hypermarket, at the time called Sokos Market, was founded in 1971 along Tampereentie in
Turku, but the following year, Jyväskylä's Seppälä Prisma was founded, and it got its name from a landmark built in connection with the
car market, which looked like a
prism. In the 1970s, Prisma/Sokos supermarkets were also opened in
Kouvola,
Oulu,
Pori,
Seinäjoki and
Tampere, among others. The first Prisma in the Helsinki metropolitan area was opened in the
Malmi district in 1987. The current form of the Prisma chain was born in 1988, when the S Group had begun to consolidate its stores under national chains. SOK considered Prisma a successful name, so it was introduced in all of the S Group's hypermarkets, the product ranges and marketing of the stores were unified. At the end of 1995, there were a total of 28 Prismas in Finland. Prisma's main competitor in Finland is
Kesko's
K-Citymarket chain.
Failed regional expansion AS Prisma Latvija was founded on January 17, 2006, as a registered S-group in Finland. Its share capital was 5,150,800 euros. The chain stores in
Latvia and
Lithuania were closed in 2017. Prisma also has 14 hypermarkets in and around 5 cities in
Estonia. On March 4, 2022, Prisma's owner, the S-Group, announced the closure of all Russian operations. In April 2026, Prisma reached a tentative agreement for sale of all 13 of its Estonian stores to the
Coop Eesti cooperative. ==Gallery of Prisma stores==