Unfortunately there is no investment visa per se that one can apply for in Sweden. Getting a Swedish residence permit by investment is therefore not possible. There is, however, one permit that is quite close to this and could be useful if you will try to move to Sweden based mainly on your wealth.
Residence permit by investment alternatives
The closest permit that Sweden has to an investment permit is a permit for being self-employed. This means that you have bought or plan on establishing a business in Sweden. If you will not be starting your own business and solely intend on getting a permit through investments you will need to prove that you have at least 50% ownership of the company in Sweden. As such, most individuals coming to Sweden in this way will find smaller companies to purchase and obtain the permit that way.
It is important to note that a permit as self-employed is not a very popular permit in Sweden. The reason for this is that the processing time is very long and can often take between 1.5-2 years for the Migration Agency to process. It is also a document heavy application requiring a lot of information. You need to prove your competence, finances, the business you own/intend on starting, your business connections, and much more. As this is a slow and complicated application, most people try to avoid this. Instead, obtain residence through other means, such as standard employment, studies, or as a dependent.
To summarize, if you do not have the time, money, competence, and connections to apply for a self-employed permit. However, it is not something that most people would advise on doing if you want to try to move to Sweden as fast and as easily as possible.