Yes in my opinion. Just look at the chart and you will see ho fast it increased. Every coin that increased this fast make a correctin in price.
You will want to look at the previos dates and you will see the same thing happened in May. I was trading XRP and XLM in that day and I lost all my gains waiting further increase in price. But it is your decision in the end.
Now lets analyze this persons recommendation to sell. He says you should sell now because he almost lost all his profit 7 months ago when the high of XRP was anout $0.35US. But, if he would have held it for 7 months, his XRP would be worth over $2.00US. So, could you sell now? Yes. Is it probable you will make more profit if you dont sell? Yes.