What you have described is trading or by extension buying and selling and this is normal. If you make profit, you have to try to sustain it by either making more profit or making less losses and by that your profit margin will be rising. So if you have made $10k in your first trade, try to sustain it by buying or selling at appropriate time. You have made a simple and normal analysis on trading, investment and it is normal hodling or selling and rebuying at intervals.