Any person may apply for a residence permit in Latvia as long as it is based on one of the legally valid reasons for requesting a residence permit. Basically a residence permit is needed if you wish to reside in the Republic of Latvia for a period of time exceeding 90 days within half a year as from the first day of entry.
In the absence of other reasons entitling to a foreigner to a residence permit under the law, a foreign national may apply for the residence permit in Latvia on the grounds of business and investment:

Residence permit based on investment in real estate, for example, purchase of an apartment or a plot of land.
Read residence permit based on investment in real estate
Residence permit based on the investment in subordinated capital of a credit institution.
Read residence permit based on bank deposit
Residence permit based on investment in the share capital of a company in the status of a shareholder, for example, company formation and registration or acceding to an existing company with a significant investment.
Read residence permit based on business investment
Residence permit for a company executive, for example, a Managing Director, Chief Executive Officer, Board Member, Proxy (read more)
See next entry - How to apply?