just check some trade group and see people say about that then if they say hold we sell. they say sell we hold

I believe that you should act upon the advice of the experts. There are very less chances that their predictions result in loss. I must suggest you to remain cool and calm at the time when prices are falling down. Holding the Bitcoin at that time is most preferable thing to do instead of just getting panic and selling them at lower rates.
What you say is true. Panic sell will only bring a trader to a loss. I experienced it several times. Better to back up losses than to panic sell.
Some of expert prediction are true but im not saying just do what ever they says sometimes its better to save if your bitcoins are came from your profit better to save then unless you don't buy them into market because once you do that and then you wait for the price increase then sell and wait for the price to become decrease i experience this kind about bitcoin pricing and this is kinda normal for it. No need to panic just wait and see its best.