Occasionally I see questions that are basically "I have X money. What do I do with it". A list could be compiled, but I feel it to not be necessary.
There are several ways to interpret these questions:
I want to outsource my investment decisions to Money@SE.
There are several issues with this version. First, it's basically "give me the codez". Second, it is a useless question - how could you possibly trust strangers on the internet, with no stake, to manage your money, rep or not? Lastly, it is unlikely that a pro-bono roving investment adviser will take up residence at Money@SE and tirelessly provide every asker with efficient strategies tailored to their status.
More likely (and what I typically see happening) is that they elicit very vague and general answers, like "look into index funds and bonds". Because of space constraints, even basic advice ends up being too general to really work with, and OP would have to read up on it anyway before they can safely go and act on it.
Of course investment can be complicated, and while relevant to many, is rarely taught by schools or other mainstream information channels. For most people, it is neither interesting nor comprehensible, and they just want to get it over with and move on with their lives. I actually sympathize with this interpretation, but nevertheless it is not possible to provide what the asker is seeking on this site.
I bet there's one asset that performs way better than 99% of the others. I don't want to spend time and effort finding which one it is, so can you guys just tell me and I'll put all my money in it?
Of course there is no "best" asset, it all depends. The only real answer to this question is it depends, it depends, it depends. Was it necessary for the question to be asked, to learn that it depends? Of course it does.
Again, I sympathize with this interpretation. There are now countless varieties of investment instruments, it's all quite confusing, and with most of them you seem to end up losing money. Surely there's one where you don't lose, and surely somebody knows which one? But of course the question is predicated on a false premise, so cannot be answered.
The amount of money at my disposal is unusual, such that typical investment advice (index, bonds, 5% in individual stocks, etc) doesn't apply. How should I invest?
Trivially, very small sums such as $10 indeed cannot be invested according to standard investment strategies. Likewise, if we're talking hundreds of millions, this is also true, but in that case, you wouldn't be asking here.
Besides that, I feel like say from 10k to 10m, there isn't really all that much that varies in strategy. 30k? Buy the index. 300k? Buy the index. 3 million? Buy the index. Do we really need multiple questions, with only the number changing, and the answer is the same advice on index ETFs, bonds, CDs and so on?
As I said above, in some cases the amount is indeed unusual. However, it seems that most people who ask these questions have very normal capitals, and apparently overestimate how unusual their situation is.
Teach me basic investment principles.
This is the only interpretation where the most likely kind of answer is actually what the asker wants. However, even so, it is impossible to give a good answer. Volumes have been written on this subject, indeed the asker would be far better served by reading those volumes. What can fit into an answer will gloss over so much that claims cannot be adequately explained and justified with evidence.
This is essentially a question that is too broad. However, it is also a very important question and deserves to be addressed on this site. The correct way of addressing it is to give OP a list of books to read on this topic, so they can come back and ask more specific questions.
I feel that whenever this kind of question ("I have X money, where do I put it?") comes up, what the person really means to ask is certainly one of the four possibilities I've listed above. Is this a correct assessment? What is to be done about such questions?