Yes there will be a significant drop not only with Appen. The issue of taking profits and advantages of this long term, runs in favour of taking profit for stock where there has been a huge leap in growth over a short period and there is high P/E. You will still gain long term if you do not sell, as this stock will rise quickly come another growth period and the race in AI with rich Asian Companies and the US competing . I have hedged with gold to reduce risks . I am not near a financial wizz or great with estimating the metrics here so keen to hear on this.