Why to people buy /Sell Crypto like there is no tomorrow?

When the market is in uptrend everyone buys like the world is ending and you won't get a chance to buy it ever again and when the market is crashing everyone sells off like it's the end of the crypto world. Why don't we do a little bit of research and invest in the technology behind the coin rather than investing blindly. I would rather HODL it for life rather than dump it in loss.

Shares your thoughts on it guys, I have invested in Litecoin, XRP, XVG and electroneum and I believe it will make me rich some day. I believe in their concept and may be I am right, may be I am wrong but I am going to hold it for 2018.