Investing without any reasoning can just make one to invest without considering the risk and the probability of making lose or making gain from the investment.
When it's about large sum of money you should do extensive research. I've in past experienced loss when my research were superficial. Sometimes the project seem too promising but turned out a cheap copy of something else that don't have the capacity of developing the network as promised and sometimes I bought a good coin but at wrong time. i.e. when it was at its peak. So, by research, you need to have a detailed look about what the progress had been made, how are the price changes from start. Even coinmarketcap chart can be confusing as they make it after they list it while the coin might have been trading for a while.