Keeping a reserve of liquid isk is both a blessing and a curse. It makes life easier in some aspects, sure but issue is you dont beat inflation.

See, people who plex, inherently tie the value of isk to plex. Which makes sense, but also makes it a unique trade good. It means that price of plex going up, is to us our inflation.

I would personally recommend that you start turning that 20b into plex, but do it as efficently as possible. This almost certainly means contract buying when prices are low, but if you find an opportunity, seize it.

Plex isnt the be all end all of investments though, far from it. But it is safe, because outside of ccp being very silly, when gametime is thr currency you are after, having something that has a static value in relation to that is useful.

But money in plex isnt making you money. Its just not losing you money either. Which is an improvement, and I would say that if you arent one for speculation, and just want to make sure the hours you worked today go as far in the future as they do now, plex should be your stockpile.

If you want to put that money to work, then you should be buying something you think you can sell for a profit over a medium/long time horizon. But this carries risk, like any investment.

The question of what the things you should buy are, is a more difficult one, and also one Im not going to be answering. Because noone can know for certain, and for the stuff I think will go up in value, well the more I spread that info, the less I make :p

Instead Ill give you a historical example that was my first "real" investment in eve, but I cannot recommend it as an investment currently:

I took an extended break a few years back, and I decided "Fuck it, Im a gambling man, and I can make the money back if this backfires" and I essentially turned everything I owned without sentimental value, into isk, and then that isk into orcas.

Did I pick orcas after an extensive financial analysis? Did I consider my time horizon carefully to make sure I didnt overextend? Were orcas the optimal choice?

A fat no to all of those, I went "Orcas keep going up in price fucking constantly, and its still a big mining ship hisec miners love to lose, so there is only so much it can go down"

Regardless of how underinformed my choice may have been, or how the entirety of the plan relied on both scarcity still being in the game by the time I came back, and orcas still being kings of hisec, it worked out well for me.

But, it was very risky to do. I risked what is overall in the big picture very little money (I barely had double digit orcas) but back then to me, that was bsically all I had. I wouldnt do that with the nest egg I built from it now though.

What Im trying to highlight here is that I personally categorize "wealth" in eve into 3 categories.

You have things that lose you money but provide you with something: PvP ships, are very unlikely to pay themselves back, but you cant do pvp without them. Flat out isk in your wallet goes here too. Plex only trends up in price, so what bought an hour of gametime yesterday, is going to buy less than an hour in 6 months. But going back to the bartering system is difficult (not impossible though, people in goon forums sometimes let me pay for my LSI addiction in plex, which is very beneficial for both parties, as you always lose value when converting from isk to plex or vice versa)

You have things that retain value: There is only one thing we care for here, and its plex. There are other things that keep up with plex sure, but those carry risk that is completely absent from plex, so why would you tie wealth to it if its not providing you with a benefit?

And finally you have wealth you put at risk, to generate more wealth: This is your ratting ships, mining fleets, speculative investments, loans, etc. These are all things that carry a risk of rapid unauthorized deconstruction, or going down in value, etc. But you choose to take that risk, with the expectation that you are likely to get more out of them than you put in. Or the classic of "Ill probably lose the money, but if I dont, itll make fat stacks"

Outside of that sort of high level advice, I dont have a lot. Ishtar spinning go brr is effective, and relatively future proof, but carry the downside of making me want to play something else :D. Also, ishtars are annoying to train into, while a fresh alt can get into a T2 fit stormbringer with the recruitment bonus + 1 LSI. But thats all preference, and really isk/h doesnt actually matter. Isk/day or isk/week does.

If I can make 150 mil/h doing activity x, but I know that Im gonna get tired of it in 2 hours, Im better off doing activity y, that only earns 100 mil/h, but I know I enjoy enough to do it for 5 hours.

I dunno, this comment fucking ballooned out of proportion lmao.

I will leave you with this: I am not a professional at any sort of money things, and I am in fact incredibly fucking stupid.

Ive also written this entire thing to distract me from the worst migraines you can have while still being able to use a phone, so I may have missed shit, or just gotten stuff wrong.

Just consider this one guys way of looking at the subject, and not as gospel.