Could you do an editing pass on your title and question please? Writing in full sentences and adding a little extra context would help a lot.

I’m confused - I think you kerfuffed your acronyms. Do you mean ROI? I feel like that makes more sense in this context. I’ve never heard of OPM, though a google search tells me it just means “other peoples money”, which still doesnt tell me much about the constraints you are dealing with.

Anyway, your intuition is correct that you should invest, not just put it into a savings account. And Apple is probably a fine stock to pick if you wanna do that. But what if Apple goes belly up tomorrow? Then you’re boned. Or, more likely, what if a combination of unpredictable market forces and executive mismanagement lead to Apple stagnating in the tech sector for years? The problem with buying blue chip stocks is that everyone else also expects them to do well. So everyone wants some of their stock, which is why the price of Apple stock is so high. Which means that if Apple does any worse than excellent, you would have been better off putting your money into some podunk company that no one cares about but which did a little better than expected.

So a better strategy is to hedge your bet. Invest some of your money in Apple, and some in podunk. But what about Microsoft and podunk 2? You could still lose out if these do better, while the former underperform. Okay, then split your money 4 ways. Now continue this pattern until you are investing in basically every company in the market. We’ve just invented index investing.

The basic concept of index investing is that you are taking each dollar you have and simply investing it in the whole market. Economists studying investing have pretty much agreed that this is the best strategy for almost anyone interested in investing in the stock market. YOU CANNOT BEAT THE MARKET. By which I mean, you can’t expect to plunk down your cash on some stock or other and expect to do better than the total growth of the whole market. Not that no one can beat the market - just that YOU CANNOT BEAT THE MARKET. After all, you are not a hedge fund with several billion dollarydoos of play money and a small army of MIT-trained quants who have been writing machine learning algorithms to predict the market for the past 40 years. So the smartest thing you can do is recognize that you are not smart enough to beat them, and just track the market - because if you start trying to be smart, you will probably underperform the market and lose out on potential gains.

So you decide to invest in an index fund. Which one? The main issue here is fees. Managed mutual funds, where a human person is picking stocks for you, often do outperform the market a bit. But they charge you for that privilege, and after you’re done paying them, you tend to have less money than you would expect. Instead, just pick a low fee index fund and be done with it. The lower the fee, the better, because otherwise index funds are essentially identical.

Now, there are ways to make more money than this that I would not recommend because it seems like you are using money you will have to pay back.

The first is investing in a more volatile index fund. Picking one stock or another because you’ve heard “it’s a good investment” down at the bar is the equivalent of choosing a bottle of wine based on how much you like the drawing on the label. Your half-baked belief in your stock-picking ability is contributing nothing of value to the market. However, one thing that almost every investor dislikes is volatility - watching stock prices go up and down constantly in wild swings. Dumb investors don’t like it because when prices go down they feel like the sky is falling, so they sell at the bottom and lose all their money. Smart active investors don’t like it because when the market is down they can’t get their money out to put into the now-cheaper stocks they want to buy. But if you are a smart passive investor, high volatility index funds are the way to go, because if you can not care about wild swings in your stock prices and just leave your money alone, then you are providing something rare and valuable to the economy, and therefore you deserve to be paid for it. Hence, over a 30 year investment period, investments in high-volatility index funds outperform simple whole-market index funds (assuming equivalent fees), even if you end up having to sell low. For you, however, if you end up having to pay the money back during a low point, you might end up having to sell at a loss, and will then, once again, be boned.

Second is investing in your own, hyperlocal market, like by buying local real estate or investing in local businesses. Investing in local businesses especially is one of the most overlooked ways to make your money work for you, and you can massively outperform the stock market. This is because in your local market,