so if I had 50000BTC siting in my address for 1 year, and I decided to move/spend 1000BTC, the days destroyed for that transaction would be 1000*365, which is not that big really when looking to the daily sum:
Thanks for the exmaple, but: If the 50'000 BTC were sitting in one address (and one utxo), wouldn't there be a 49'000 BTC change-back output too on that transaction? Would that output be excluded from the BDD? What if the change-back went to a different address?
If someone has 100BTC that they received a week ago and they spend it then 700 bitcoin days have been destroyed. If they take those 100BTC and send them to several addresses and then spend them then although the total transaction volume could be arbitrarily large the number of bitcoindays destroyed is still 700.
I was trying to understand that as well, but I often see small transaction from large holding addresses (for example BTC-e's cold cold storage or Bitsamp's cold storage) where they send only a couple thousands of coins to a new address, after checking the days destroyed chart I don't see any spike !!!
For example watch
this transaction it took place 28-08-2014 and it is Bitstamp sending 3000
BTC to an address and the change to another address, now this is how the days destroyed looks like that day:
