Alex found that he was a person who held a 10% stake in the Oak Corall, one of the biggest and most reputable organisations in the world. He surrendered all his share in the King's Rocks, and agreed to pay a large amount of money after he received the royalties from the book Eeveelutions to the Oak Corall, and also pledged his shares on the Moss Stones and Ice Stones. He also agreed for the name 'Researcher Burns' being attached to Oak Corall and a few other such conditions regarding the interests of the organisation.
In return he recived 10% of the shares of the Oak Corall. Oak Corall was a massive organisation that while did not have much commercial activities, made a tremendous amount of money every year. Some came from the large number of trainers who were paying fees for storing their excess Pokemon in the ranch, which had the highest standards and best reputation among all its competitors offering similar services. Some of it came from the large amount of sponsored individuals, both who were currently being sponsored and were sponsored in that start before attaining self sufficiency, after which they became independent. Many individuals would apply for a sponsorship because Oak Corall had the least conditions and offered the bedt benefits for the conditions, and you didnt have to be bound to the Oak Corall upon completion of the sponsorship. While they wouldn't make any direct profits, the enormous interest chain they would form, allowing the trading of information, Pokemon and items all across the world both with the Oak Corall or with other individuals or organisations through the Oak Corall brought massive profits and to Oak Corall.
Most of it came from the many research projects that had been completed and successfully brought profits afterwards. The Ice Rocks and the Moss Rocks for example, would be a stable source of profits for years to come. At least for 50 years, no one else could sell these two products. By the time this period was up, Oak Corall would have a monopoly on its sale. Similar to these two new products, there were dozens of other exports from the Oak Corall, like the liquid metal coating which could enhance the defense of Steel types, the specially processed minerals that could help the growth of Rock types, incubation fluid for many different Pokemon being some of the more popular ones. The Oak Coarall made a massive profit from all these products.
In theory, barring any major expenses, Alex could earn back all the money he invested and had promised to invest in less than 10 years.
This was all not mentioning the sale of Pokedexes. The Pokedex was developed by the Oak Corall a few years ago. It wasn't really used much due to manufacturing difficulties, and only available to those sponsored by the Oak Corall and a few other select places.
But technology was rapidly improving. In a few years, Alex thought that the difficulty of manufacturing the Pokedex may drop sharply, and the whole world would want one when it was available. The Pokemon Allaince had already been speaking with the Professor about the mass manufacture of Pokedexes. This would give another large source of profit to the Oak Corall when it finally happens.
Lastly, and most importantly, being a shareholder of the Oak Corall would mean he had the support of Samuel Oak. One of the stongest, richest, and most well connected person in the world, Professor Oak could make his rise to power in the future much easier. Also attached to Professor Oak were two other Champions, Blue Oak who was his grandson, and Red Fires, who was his protoge. Whatever he wanted to do later, this support would prove invaluable.
As for why Professor Oak was willing to support him, Alex thought he knew the reasons.
First, he was a Dark. Whatever he did would mostly be undetectable to most of the powerful Psychic type Pokmeon unless he was in their immediate vicinity. Hence, any action he took, for example the King's Rock purchase, would go undetected.
Also, Professor Oak revealed that many people had tried to use Psychic means to spy on Project Fairy. But they had failed, partly due to the effort of Alakazam, and partly due to a Dark being deeply involved directly in the research aspect. Any project he took part in and action he did on behalf of the Oak Corall would mostly go undetected in the future, as his powers improve. For such reasons, having a trustworthy Dark was very useful.
Secondly, Professor Oak admired his research capabilities and analytical thinking. He had already made a lot of contribution to the Oak Corall, and was confident he could do more. Alex was already planning about the Nature Table and the evolutions of Magneto , Electabuzz, Rhydon and Magmar already.
Thus, Professor Oak wanted to tie Alex to his organisation and himself.