When the building of Ainola was completed, Sibelius realised that he was in possession of real estate for the first time in his life. Now, he could obtain a loan without having to find a guarantor, since the estate of Ainola was accepted as security. At the start of the 1900s Sibelius also had some shares in banks and insurance companies. He had inherited them from his relatives. These paper securities turned out to be useful during his financial difficulties in 1910-1920. By selling them he could pay off a few loans.
The wealth he rapidly acquired in the late 1920s allowed him to become an investor. In this project he had expert advice from Katarina’s husband, the bank manager Eero Ilves. The results can be seen in Sibelius’s tax return for 1950:
| KOP [bank] | 1,097 shares |
| KOP (new) | 974 shares |
| Riihimäen Lasi Oy [glassworks] | 474 shares |
| Suomen Sokeri Oy [sugar factory] | 200 shares |
| Vakuutus Oy Pohjola [insurance company] | 30 shares |
| Keravan Telefooni Oy [telephone company] | 7 shares |
| Tuusulan kansanopiston kiinteistö Oy [folk high school] | 5 shares |
| Keravan Yhteiskoulu [co-educational school] | 2 shares |
According to the deed of inventory on his death, he left a considerable estate in 1957. His daughters sold Ainola to the Finnish state for a very reasonable price in 1972. Thanks to them the home of the composer is now the property of the Finnish people.