It depends on market research

I invested BRL 5,000 on Christmas and on the same day my portfolio had a total value of BRL 5,429. The next day my portfolio had BRL 4,890. It wasn't the volatility that changed the value, it was a bug. I don't think anyone who invests that much gets a 10% advantage on the same day. Or am I wrong? Did the volatility really get to me?