The stock market rally was broad, with several of the heavyweights up 5 to 7 percent. Truck manufacturer Volvo AB topped the list, up 7.7 percent. Boliden, Atlas Copco, ABB and Sandvik all rose between 5 and 7 percent.
This followed the US and Iran agreeing to a two-week ceasefire that also includes reopening the Strait of Hormuz, allowing oil exports from the Persian Gulf.
Overnight, Asian stock markets rose similarly. Tokyo closed more than 5 percent higher, and in the US, futures point to gains of around 3 percent.
On Wednesday afternoon, concerns about the agreement emerged after extensive Israeli attacks on Lebanon, resulting in a large number of deaths. Reports in Iranian media suggest Tehran may withdraw unless the ceasefire also includes Lebanon. However, the concerns did not affect investors in Stockholm.
The price of oil has plummeted and is currently around $95 a barrel for North Sea oil, up slightly from last night's low of about $90 a barrel.
Market interest rates have also fallen sharply. Swedish bond yields are down between 0.15 and 0.20 percentage points, which could put downward pressure on banks' mortgage lending rates, among other things.
The krona has strengthened considerably. One dollar cost 9.29 kronor this afternoon and one euro 10.86.
Corrected: In a previous version, the wrong final figure was given for the Stockholm Stock Exchange's rise.
