I see your point, trading out of greediness can result to a failure, better to trade when you are well prepared and not just trying to add more with your winning streaks, there are many factors that will affect you, having that kind of confidence which most of the time reflects in making mistake, not saying that you won't succeed but if you are not well prepared and you are just aiming to earn more, it's a risky way of trading and can ends up losing your investment.
usually such trading out of greediness is because to compensate previous lose or we are so sure that the coin we trying to buy are gonna grow within short amount of time honestly if we know that there's something that gonna come up that might increase the price significantly such as news about listing and so on then its okay to be greedy with trading that coin but i think its not fine if we are making decision when we are hot headed because previous lose.
I've experienced plenty such thing and always further lose is what I get.
therefore indeed trading with cold head is definitely gonna yield a lot more result than being aggravated into thinking that by going all in we might compensate our previous lose, try to reason then we might find profit at the end of the day.