One should avoid such people and also use our own research in buying/selling the coins. This people work for their benefit only and they will only want to have their own profit. So always follow you own research and instinct and not to get even panic when some fall happens as it could just for a short term and in longer time the market can recover quickly or may take times but will happen eventually. Also do not invest in any coin said by anyone unless you think it is good to invest in it.