yes, of course you can.  it depends on how mentally he is in investing in bitcoin and also his predictions.  But don't worry, when bitcoin falls, it's an opportunity to invest, imagine! in March 2020, bitcoin price was $ 3200.  and now $ 18,000.  If in March you invested just 1 bitcoin, then your profit today is $ 14800.  extraordinary.  How if you invest 1,2,3,4 bitcoin, the greater your profit.