I guess this op just looked into the future before making this post. When this was made the 521 BTC isn’t worth up to a million, but check now, it is worth more than  one million dollars. If you check with the current rate of bitcoin, it is around $24,000,000 (twenty four million dollars) that’s a really huge amount of money today for anyone to hold. Imagine if this guy was able to hold that 521 BTC from then till now, he will be very happy with himself and will be smiling to the bank. This is why it is good to buy and hold your bitcoins for a long term. You’re sure going to be happy that you did.