If you have that kind of money and you want to invest in newish tech, then you have to accept the fact that your investments will move the market and make that work in your favor. Retail can buy a share here and there but you cannot. So how to make it work in your favor? Ask yourself "who can make productive use of this much money? who needs this much money to even be viable?" And it will be really capital intensive moon-shot type stuff. Self driving cars for instance, but that might already be overcrowded now. AGI in general too, that's kind of a more uncertain bet. Europe needs a shitton of energy investment now, both for geopolitical reasons but also to charge all the electric cars they will start buying soon. Building those nukes or solar+batteries can easily absorb hundreds of billions of dollars. Then there is medicine and biotech but that might take a lot of savvy to capture the value you create by spending on r&d. But like nanobots and brain coprocessors and immortality and stuff that is something we will eventually build and it's not that out of reach. Might wanna figure out some intermediary profitable goals. In summary take a long hard look at what Musk is doing. Except maybe his twitter persona.

Edit: Might wanna take a look at Gosplan too. After all a sufficiently rich investor is indistinguishable from a plan economy planning committee.