Sometimes buying at the top has its benefits (take bitcoin up until around, eh, $17,000 USD let's say), but it's few and far between.
It's hard to tell where the top is sometimes, especially as the market gets more saturated. Hardly anyone is into crypto, but now that it's becoming more mainstream, the inflow of mainstream money is pushing a lot of these coins up.
I think this is really due a lot to the buy-in structure. You don't need to buy a full "share" of a currency like you do with stocks. Why buy a share of TSLA when you have to pay over $300 for it, when you can buy $300 worth of ETH or LTC (both of which seem to be gaining much faster than Tesla or most other major Wall Street stocks)?
You're 100% right though: knowing the whitepaper and being able to tell the BS from the real deal is key. So many scams out there ...
RE: Research to learn, then you can make money